As demonstrated by Great Bay, the Radius team seems to excel in second restaurants, where there is more focus. Although Italian cuisine and chef-selected seafood and vegetables are common in Boston, few such menus are as successful as what I tasted recently at Via Matta. True, the heirloom tomatoes and fresh herbs were in every farmer’s market, but they were not on every restaurant’s menu, and the extraordinary pastas and splendid seafood at Via Matta should hold up all year. It’s enough to make me wonder whether Radius itself has transcended my initial mixed impression. Certainly there is very little mixed to report about Via Matta. It’s expensive and worth it for appetizers and desserts, moderately priced and impressive for smallish pasta plates and entrées.

Actually, the pour of oil with the breadbasket is a little disappointing. It’s deep green, like some of the best olive oil, but has very little flavor. The bread itself, Iggy-style French bread cut from large loaves full of holes, is chewy and delicious. There is a sprig of fresh thyme tucked into each napkin, so add some of that to the oil.

The grandest of the real appetizers is the chilled-shellfish-and-citrus salad ($17). It’s really a raw bar of succulent seafood without shells or actual fruit, just a citric dressing that approximates ceviche without actually changing the texture of shaved octopus, squid, lobster, clams, and scallops, interleaved with some parsley and a few fine strips of red jalapeño pepper. I was also impressed with the crispy polenta with lobster ($17), three meltingly rich diamonds of cornmeal mush, crisp at the edges, with about a third of the meat of a chicken lobster — again exquisitely tender but cooked through — served with some halved cherry tomatoes and basil.

More typically Italian is the antipasto di magro ($10), an all-vegetarian platter with a couple of surprises: no roast peppers, batons of something chewy like salsify, and interestingly sweet shredded onions. The grilled squash and eggplant are more predictable, but excellent, as are the tiny black olives, sautéed broccoli rabe, and grilled asparagus. I wasn’t knocked out by the button mushrooms, but at least they weren’t over-marinated.

Spicy calamari ($13) is a modest portion of finely sliced squid rings, sautéed in a tomato sauce, with garlic toast made of that excellent bread. I think this dish might work better cold, but it certainly is good eating hot.

Likewise, the local-heirloom-tomato-and-herb salad ($14) is fully up to speed with shavings of fresh mozzarella, fresh basil, and cilantro, on perfect tomatoes including some Cherokee black, green zebra, and superb cherry tomatoes in several colors.

Pasta courses are small enough for a middle course, but also make very decent entrées. The "chitarra with Nonna’s lobster and shrimp ragu" ($23) has a thick, lovely tomato sauce with nuggets of seafood. Unlike the chef, Nonna probably cooked the seafood in the sauce, to the detriment of the lobster and the advantage of the sauce. But the maccheroni alla chitarra (a chitarra is a contraption of wire strings used to cut sheets of pasta into square spaghetti) would earn her smile of approval, toothsome and enticing as only fresh pasta can be. Maltagliati ($18), which means "badly cut," is here badly cut into sheets, which pair well with the guinea hen (a kind of darker dark meat) and chanterelle mushrooms. Again the pasta is very "bitey" in a way that is hard to do with even the best factory pasta.

Conventional entrées aren’t enormous either, which will suit most diners. Hungry folks can add (or perhaps divide) a pasta course, or order one of the "contorni," or steak-house-like side dishes; the grilled asparagus ($8) is excellent, with just a bit of browning and plenty of concentrated vegetable flavor. Grilled swordfish ($28) is very good, though not medium rare as promised. A decent swordfish steak sits on some giant white beans and cherry tomatoes, providing alternate bursts of starch and vegetable heaven. Pollo al mattone ("chicken under a brick," $22) seems to get sautéed under the brick, with a nice salty crust over tender breast meat, and some chard for contrast.

The wine list is all-Italian, which used to be good news for red-wine drinkers and trouble for white-wine drinkers. But Via Matta has gathered a fair representation of the crisper whites coming from Italy these days, which use California technology and more northern varieties. Our table, however, worked through the red wines by the glass. Interestingly, the cheapest red listed, a 2001 Michele Chiarlo Barbera d’Asti ($7), was best with this food, with plenty of berry-like fruit and flavor. The most expensive, a fully aged 1993 Marchese di Barolo ($16), had more structure, but not a lot of flavor or bouquet. It may have been handicapped by a larger pour in rather small glasses — larger glasses come to the table when you order by the bottle. A montepulciano from Umani Ronchi ($8) fell between the previous two in style, and a Maculan merlot ($10) was as soft and rich as the barbera, but not so lively.

One has that strange choice of waters at the beginning of the meal. Boston tap water tastes fine to me, but San Benedetto frizzante ($5.25) is pretty good, with an intriguing hint of spritz. With desserts, a decaf espresso ($3.75) was very short and bitter, probably the best approach to decaf espresso. Wild-mint tea ($3.75) was served in a one-piece open pot, but brewed well.

Desserts were a real highlight in a meal that had no lowlights. The knockout was the trio of three traditional semifreddi ($9), pots of chilled mousse flavored with sesame, white chocolate, and espresso. The sesame makes a marvelous mousse, very rich and subtle, hard to pin down. The kitchen gets something of the same effect from sunflower-seed gelato with orange-scented olive-oil cake ($9). This is a heavy cake, possibly farina, and sort of soaked in what seems like orange-flower honey, with a sour-creamy filling for relief. It’s the kind of dessert you deserve for being good and not having both a pasta course and an entrée. If you haven’t been so good, you can probably fit in some panna cotta ($9), here not too jelly-like, although layered with preserved peaches in a parfait glass. Or you could have the chocolate terrine ($10), which is less like mousse and more like biscotti or candy than most restaurants’ idea of a chocolate terrine, and refreshingly contrasted with "almond snow" — a granita-like Italian ice.

Service at Via Matta is quite good even when it’s full — and this is a popular and successful restaurant. Any problems most likely result from the loudness of the room, as when our entrée order was incorrectly taken, or when we ordered "still" spring water and got frizzante. The wood floor is loud, the painted yellow walls and ceilings are loud, the etched-glass screens and large windows are loud, and diners talk enthusiastically about the food, making it still more loud. Not too loud to taste, however.

Robert Nadeau will be signing and discussing his book, The American History Cookbook, at the Harvard Book Store, Cambridge, on September 16, at 6 p.m. He can be reached at RobtNadeau@aol.com