Sebastopol chef shares secrets to grilling up a great smash burger

Chef Bob Simontacchi's Sonoma Burger is opening a new snack shack Saturday at the long-shuttered concession stand at Spring Lake.|

Memorial Day weekend marks the unofficial start to burger season, and the burger that seems to be taking the nation by storm, including Sonoma County, is the smash burger.

They’re on menus at Willi’s Wine Bar in Santa Rosa and Wurst in Healdsburg. Sebastopol seems to be smash-central, with three restaurants within about a mile of each other listing smash burgers on their menus. Blue Ridge Kitchen and Fernbar in The Barlow have them, and then there’s Sonoma Burger, a restaurant focused solely on the smash.

“I want to cook a burger I enjoy, and this is what happened,” said Bob Simontacchi, Sonoma Burger’s chef and co-owner along with Brandon Parkhurst, the general manager.

Like for so many restaurant owners, the pandemic forced them to diversify from fine dining, which they still offer at Gravenstein Grill, Sonoma Burger’s sister restaurant. During the shutdown, Parkhurst said, the pair trialed a couple of pop-ups. One was Pleasant Hill Pies, selling pizzas. The other was what would become Sonoma Burger, and it stuck.

They found an ideal location for it just across Pleasant Hill Avenue from Gravenstein Grill in the former Giovanni’s Deli, tucked in the corner of a strip mall. The two have taken Sonoma Burger on the road to events and fundraisers to get the word out, and they’re opening the Sonoma Burger Snack Shack at the long-shuttered concession stand at Spring Lake, Saturday, May 27. The snack shack will serve burgers, hot dogs, vegan options, seasonal slushees, beer, and wine, noon to 7 p.m. Saturdays and Sundays.

What’s a smash burger?

Smash burgers have become increasingly popular, thanks in part to the rise of a Denver-based restaurant chain called Smashburger, founded in 2007. But the concept of smash burgers goes back much further.

Some credit the dish to Dairy Cheer, a fast-food spot in Kentucky that was making the burgers in the 1960s. Other sources say it’s a Great Lakes tradition, while more internet sleuthing points to the Steak ’n Shake chain, which has been around since 1934, as the true originator.

However it started, the idea is pretty simple: beef patties, smashed thin so as much meat as possible makes contact with a sizzling-hot grill.

Smash burgers have their detractors. Those looking for a big beefy patty find this style of burger lacking. But smash style is exactly how Simontacchi likes it.

“I like to be able to order a smaller burger, have a shake, have the fries. I like to have all three components together and not be totally like I need to take a nap afterwards,” he said.

He also likes it from a sustainability standpoint, as the movement to reduce meat consumption gathers traction.

“Everyone can enjoy a burger without so much meat,” he said. “You can have a good burger with less meat. Everything that goes along with raising cattle, we can enjoy, but we can enjoy just a little less (of it).”

Building a better burger

“The reason we named it Sonoma Burger is because we were able to source everything for the restaurant from Sonoma County,” said Simontacchi, who became interested in food while stationed with the U.S. Air Force in Europe.

He served in Operation Desert Storm, and after leaving the Air Force, attended culinary school at City College in San Francisco on the GI Bill.

It’s that training that makes Sonoma Burger a cut above a regular burger joint. Sauces and pickles are made in-house. Then there’s the golden, toasty buns, with their alluring sheen.

“A great burger starts with a great bun,” Parkhurst said about the several hundred Parker House-style buns baked fresh in-house each day.

“Part of the concept is starting with a great handcrafted bun to put that burger on. A real focal point of the restaurant is building the burger around the bun,” Simontacchi added.

The beef comes from Sonoma Mountain Beef Co. The cattle graze the grassy hills of a ranch in Bodega, raised by Jamie Mickelson, who Simontacchi said is “adamant about happy cows.

“You can truly taste the difference,” Simontachi said. “Start with higher-quality ingredients. They make all the difference in the world. If you want something good, you’ve got to start with something good.”

Bacon is from Sonoma County Meat Co. Turkey burgers are made with Willie Bird turkey from Willowside Meats. Little gem lettuce comes from nearby farms like Singing Frogs or Longer Table. When tomatoes are in season, Simontacchi buys them locally.

The commitment to local goes beyond the burger. Milk and ice cream for shakes come from Petaluma’s Double 8 Dairy, and there’s always a seasonal flavor: most recently, strawberry made with fruit from Stony Point Strawberries.

During apple season, they serve a Gravenstein apple slushie with fruit from Hale’s Orchard, less than 2 miles from the restaurant. Even fountain drinks are locally sourced from 55 Mile Craft Soda, a Santa Rosa-based cola maker.

In addition to good ingredients, having the right equipment is key to making sure the burgers are a smashing success. The No. 1 thing to know about smash burgers? Cooking them on a grate isn’t going to work.

This is a job that calls for a flat-top grill if you have one, or a cast-iron skillet or plancha. You’ll also need something to flatten them with. Kitchen stores will try to convince you that you need a fancy burger press, but anything that can mash it down, like another heavy skillet, is fine.

Simontacchi highly recommends using parchment or waxed paper on top of the patty to keep the meat from sticking to whatever you press it down with, and to prevent cross contamination.

Also, this isn’t a job for a flimsy plastic spatula.

“You want a proper spatula, ’cause what’s going to happen, you can really end up breaking the burger into bits. You want a really strong, not very flexible spatula.”

Putting it together

Cooking the burgers might be the first thing on your mind, but it’s actually the last thing to do, according to Simontacchi and Parkhurst.

“Have ingredients sliced and ready to go. Have your cheese all separated,” Simontacchi said. “I have everything ready to go in front of me, and then I cook. Once you’re ready to cook, it all comes together really quick.”

They recommend toasting the buns first so you can give them and the burgers your undivided attention.

Simontacchi experimented with precut buns and said they just didn’t toast the same. If you’re not making your own buns, look for some you have to slice open yourself, because they’re fresher.

He brushes the sliced buns with butter, then places them cut side down on the cooking surface until they’re bubbly and crisp, to add another layer of texture to the burger. He uses a charger to lightly flatten them while they cook, but a lightweight cookie sheet will work, too.

“Some people are all like, ‘I’ll do them in the broiler in the oven.’ Boom! There goes your buns,” Simontacchi said. “Don’t leave the buns while they’re toasting. Make sure your buns are taken care of and they’re not burnt.”

Once the buns are nice and toasty, slather both slices with sauce. Then it’s time for the meaty main event.

Simontacchi takes a ball of meat 2½ to 3 ounces, maximum, or the patty gets too big when pressed out, he said. He seasons the ball with a healthy pinch of salt and pepper, adds a bit of butter to the pan or grill, puts the ball on the grill, then smashes.

“There’s a little technique to getting it out,” Simontacchi said. “You want to really push it out, pushing all the way down. You smear it out a little bit. The edges will start to break apart. They’ll start to fray, and those get all crunchy.”

The burgers being so thin can pose a challenge for flipping, which is why a quality spatula is important.

“What I do, I invert the spatula and really get underneath it to release it and then flip it over,” Simontacchi said. It may take a little trial and error at first, he said. The burgers are cooked in about three minutes.

While Sonoma Burger offers a variety of burgers from turkey to tempeh as well as a choice of toppings, Simontacchi prefers a classic burger, topped with American cheese, an ingredient for which he makes no apologies.

“A good burger is (more than) the sum of its parts,” he said. “When it’s composed properly, it’s really good.”

Sonoma Burger Smash Burgers

Makes 5-6 patties

Smash burgers don’t require fancy ingredients. It’s all about the process.

1 pound ground beef/chuck, chilled

Salt and pepper


Sliced cheese (optional)

6 buns, sliced and toasted (see following recipe for homemade)

Sonoma Burger Nearly Secret Sauce (recipe follows)

Bread & Butter Pickles (recipe follows)

Lettuce, tomato and onion, for toppings

Form beef into five to six 2½- to 3-ounce balls, about the size of a small lime.

Preheat a flat-top grill, griddle or skillet over medium-high heat. When the cooking surface is hot, season each beef ball with a healthy pinch of salt and ground pepper.

Drop a teaspoon or so of butter on the cooking surface. It should melt quickly, but be careful to not let it blacken. Put the beef ball on top of the melted butter and, using a burger press or a heavy-duty spatula, press down very firmly to make a thin patty. Working quickly, repeat with remaining beef balls. The edges may crack, which is what you want.

Cook each patty about 1½ to 2 minutes. Then, using a heavy-duty spatula, carefully scrape and lift the patty to flip it. It may be easier to use the backside of the spatula to help with the scraping and lifting.

Once flipped, add cheese, if using, and cook another 1½ minutes or so until cheese is melted.

Remove immediately to a platter or directly onto a prepared toasted bun and add toppings.

Sonoma Burger Buns

Makes 12 buns

Bob Simontacchi believes great burgers start with great buns. It may seem daunting to make buns from scratch, but imagine how impressed your dinner guests will be when you tell them you made the buns yourself. If you’re going to buy them, make the effort to find high-quality, fresh, unsliced buns.

1¼ cup warm water (90 degrees)

½ ounce dry active yeast (2 packages or about 5 teaspoons)

⅓ cup sugar

1 medium russet potato

2½ ounces unsalted butter (about 5 tablespoons)

1½ ounces vegetable shortening

2 teaspoons salt

1 egg yolk

5 cups all-purpose flour

Peel and dice the russet potato into 1-inch pieces. Put into a small pot, cover with water and simmer until potato is fully cooked. Drain and pass potato through a ricer or food mill (if you don’t have a potato ricer or food mill, shred on a box grater). Leave grated potatoes out on a tray to cool.

Combine yeast with warm water, then whisk and allow to sit for approximately 15 minutes. Water should be foamy on top when yeast is activated and ready to use.

Combine butter and shortening in a saucepan and warm over low heat until liquid. Do not burn!

In a stand mixer, combine yeast, water, sugar, potato and egg yolk. Slowly whisk in liquefied butter and shortening. Combine salt and flour in a separate mixing bowl, then add to the stand mixer. Mix with a dough hook on low speed for 4 minutes. Let the dough rest for 10 minutes, then mix on low for another 8 minutes. Transfer dough to a container that has been coated with nonstick spray. Cover tightly with plastic wrap, and allow dough to triple in volume, approximately 1½ to 2 hours.

When dough has tripled in volume, punch down, turn out onto a non-floured work surface, then portion into 3-ounce balls, approximately the size of a tennis ball. Roll each into a tight ball, and transfer to a parchment- or silicon-lined sheet tray, with equal space between each dough ball. Cover loosely with plastic wrap and allow balls to proof until they are about 2½ times their original size.

Heat oven to 350 degrees (use the fan setting if you have it). Cook buns for 15 minutes, without opening the door or rotating buns. The buns should be a rich golden brown, but if they’re not, rotate them and continue cooking for 1 to 2 more minutes.

Cool for at least 1 hour before using. Do not slice buns until you are ready to use them.

To toast buns: Cut buns in half and brush with melted butter and cook, face down, on a preheated skillet or griddle over medium to medium-high heat, 3 to 4 minutes. Watch them carefully. They should be golden and bubbly. Remove to a platter for serving with burgers.

Sonoma Burger Nearly Secret Sauce

Makes 2 cups

2 cups mayonnaise

3 tablespoons soy sauce

¼ cup brown sugar

3 tablespoons Worcestershire sauce

8-10 cloves fresh garlic, minced or pushed through a garlic press

1 bunch chives, finely chopped

1 teaspoon fresh cracked pepper

Combine all ingredients in a bowl and whisk well. For best results, make at least several hours ahead of time to allow flavors to mingle.

Bread & Butter Pickles

Makes approximately 1 quart

Sonoma Burger’s Bread & Butter pickles are just the right balance of sweet and tangy. Make these at least a day before you plan to use them. Once made, they’ll last in the refrigerator for up to a month.

2 pounds of pickling cucumbers

1½ cups apple cider vinegar

1¾ cups sugar

¾ cup water

1 teaspoon salt

3 garlic cloves, chopped

1½ teaspoons mustard seeds

1 teaspoon celery seed

2 bay leaves

½ bunch dill, chopped

1 teaspoon ground turmeric

Wash cucumbers well, cut into ¼-inch thick discs and place in a large bowl.

Combine all remaining ingredients except cucumbers in a saucepan. Whisk well and bring to a boil.

Remove from heat and immediately pour hot liquid over the sliced cucumbers. Cover container tightly with plastic wrap or a sealed lid so no steam or heat escapes. Allow to cool completely, covered.

Once the pickles have cooled to room temperature, remove wrap or lid. Put a small piece of parchment paper directly on top of the cucumbers and a small object to weigh it down, to ensure all pickles are submerged. Refrigerate for at least 24 hours before using.

Sonoma Burger Turkey Burgers

Makes 7-8 patties

1 small yellow onion, in ¼-inch dice

1 red bell pepper, in ¼-inch dice

1 tablespoon olive oil

1 pound fresh ground turkey thigh meat

1 whole egg

½ cup breadcrumbs

½ teaspoon ground coriander

½ teaspoon ground cumin

½ teaspoon ground fennel seed

½ teaspoon ground mustard seed

In a large skillet over medium heat, saute onions and peppers together in olive oil until soft, about 2 to 3 minutes. Set aside to cool.

In a large bowl or a stand mixer with a paddle attachment, combine all ingredients and mix well.

Chill mix in refrigerator for 30 minutes to 1 hour. Portion into 2½-ounce balls, approximately the size of a lime. Proceed with the instructions for Sonoma Burger Smash Burgers.

This story has been updated to announce the opening of the Sonoma Burger Snack Shack at the long-shuttered concession stand at Spring Lake, Saturday, May 27.

You can reach Staff Writer Jennifer Graue at 707-521-5262 or On Twitter @JenInOz.

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