The doors at Scopa, the Italian restaurant on the north side of the Healdsburg plaza, open at 5:30 every afternoon, and despite the early-bird hour, there's usually a gathering of customers waiting to get in.

You might think it's because the room is narrow with limited seating, and quickly fills up, so they're seeking a spot before the dinnertime crowds arrive. But if you know the dishes chef Ari Rosen prepares at Scopa, you know why they're waiting: the food is extraordinarily, surpassingly good.

By the way, if you can't get in, try going around the corner to Campo Fina, the Rosens' other restaurant, with food just as good.

Even when Italian food is indifferently prepared, it can still be pretty tasty. But Rosen does nothing indifferently. His dishes, especially the ones based on southern Italian regional recipes, never become clumsy or over-embellished. If there are tomatoes involved, they're always used in perfect proportion to the overall balance of flavors. He has a light approach to a cuisine that too easily can become heavy.

For instance, think of a head of raw, chewy, bitter radicchio. Rosen turns up the BTUs on the stove and makes a classic Grilled Radicchio ($11.50, 4 stars). The heat softens the raw leaves, rendering them tender. It mellows the bitterness, but not completely. And it brightens the natural sweetness and spiciness of the chicory, a family of edible greens of which radicchio is a member. He dresses the grilled head, which loses its red color in the heat, in a dressing of sweet, rich, balsamic vinegar, tangy and acidic citrus, and pungent olive oil, faceting its flavor profile. To add some fun, he sprinkles the dish with candied walnuts. It's simple, brilliant, and perfectly accomplishes the refinement he's after.

The chef's co-owner and wife, Dawnelise Regnery Rosen, runs the room and knows good service. She's hired a staff that radiates "amicizia," or friendly good will, as it professionally performs its tasks.

The bulk of the wine list is selections from northern, central and southern Italy, both white and red. There's only one Italian red by the glass, which turns you to the bottles, where you'll find the outstanding 2009 I Favati Aglianico for $44. Aglianico has been grown on the slopes of Vesuvius since Etruscan times. Corkage is $20.

Dinner opened with a Burrata ($12.75, 4 stars), a pouch of mozzarella filled with melty-creamier mozzarella, served with grilled and crusty Italian bread and a delightful Calabrian hot pepper jelly that piques the milky mildness of the cheese.

Roasted Broccoli ($9.50, 3 1/2 stars), rather than made with round florets of ordinary broccoli, was the flower buds of broccolini, roasted to a dark green with an intensified taste. These become quite soft from the cooking, so chef Rosen tosses them with crunchy bread crumbs for texture. Pine nuts offer a complementary flavor to the greens, shavings of pecorino sheep's-milk cheese give a strong savory hit, chilies brighten the dish, currants sweeten it, and a bit of anchovy adds some foundational funk. It sounds over-the-top, but it falls together beautifully into a balanced whole.

For something airy, we found a Crab Salad ($14, 3 stars) on the nightly specials. It was loaded with freshly-picked dungeness crab in a light creamy sauce with mung bean sprouts, baby arugula leaves, and blood orange segments.

Chef Rosen has turned his attention to the toe end of the Italian boot and the region of Calabria. Polpette Calabrese ($11.50, 3 1/2 stars) is a not-to-be-missed appetizer of four delicately spiced meatballs with smoked mozzarella and a flavor-packed tomato sauce.

Nonna's Tomato-Braised Chicken ($18.50, 4 stars) arrived in a small iron cauldron with an iron top and showed a perfect balance of chicken, tomatoes and soft, cheesy polenta with sauteed greens.

It's back to Calabria for Tomasso's Sugo Calabrese ($17, 4 stars), as good a dish of thin spaghetti as you'll find this side of Reggio, made with a rich, tomato-braised beef and pork rib sugo and elevated with shavings of pecorino romano cheese.

For dessert, we couldn't resist the Molten Chocolate Souffle ($9.50, 3 stars), a well-made souffl?with crusty sides and a molten chocolate center.

(To sum up: Scopa is one of the finest restaurants not only in Sonoma County, but in the entire Bay Area.

Jeff Cox writes a weekly restaurant review column for the Sonoma Living section. You can reach him at jeffcox@sonic.net.)