Italian cuisine has, by and large, become an integral part of America’s culinary melting pot.

Spaghetti, lasagne, risotto, chicken cacciatore, ravioli, veal parmigiana and, the newest entry in the lineup, bruschetta, are all familiar offerings on restaurant menus. In fact, home cooks have worked one or more of them onto the family dinner table.

But not all of Italy’s culinary treasures are as well known. For example, few of us have had the temerity to order up a bowl of spaghetti tossed with sea urchin roe (ricci in Italian), or sunk our teeth into a roll containing farmer’s cheese and deep-fried spleen (the Italians call it milza), both specialties of Italy’s large island region, Sicily.

Equally unknown are the specialities of the Mediterranean’s second largest island, Sardinia, another maritime-influenced region of Italy.

Here we find a spreadable delicacy, bottarga, made from the roe of sea mullet — unlike any other found in Italy.

There’s also fregola, a tasty toasted couscous-like pasta of Moorish heritage that became a staple of Sardinian cuisine centuries ago. Local durum wheat is used in making fregola — nutty, round, toasted pasta used in soups and ragus — and maloreddus, thick and compact ridged pasta also known as “gnocchetti sardi”, or “little Sardinian gnocchi.”

The Sardinian table features most often the sea’s daily catch, says native Fabrizio Castangia. “But Sardinians also like lamb, simply grilled, or some meats braised in wine that we call spezzatino,” he adds. “Lamb is often used for the ragu‘ that we serve with gnocchetti sardi.”

Sardinia’s livestock produce some of Italy’s finest cheese, such as Fiore Sardo and Pecorino Sardo. Today, more connected to the mainland than in the past, the island now grows almost one-third of Italy’s organic produce.

Earlier this year, Castangia teamed up with longtime friend Alessandro Baratella to re-open a longstanding restaurant operation that for years was known simply as The Depot. And while a number of traditional Italian favorites are staples on the menu at Fabrizio’s Restaurant, the chef is serving up Sardinian favorites as part of his daily specials offerings at the landmark.

Castangia says Sardinians enjoy simple cuisine. Lamb chops are seasoned only with salt and grilled to desired doneness, then plated with fagiolini and a fresh garden salad, or maybe with roasted potatoes and Swiss chard.

The meal might begin with a small bowl of soup or a plate of fish or beef carpaccio. Grilled or deep-fried asparagus is a seasonal favorite. Sardinians eat their pasta as primi piatti, or a first course, followed by simply grilled meat or fish, accompanied by freshly harvested vegetables.

“We don’t use many sauces,” Castangia advises. “If there is some dish with sauce, then it’s probably something from another region.

“If we cook something together in one pot, then it would be served in its own juices, or with the wine ragu‘ in which it’s cooked.”

For example, he notes that lamb is often cut up and cooked with artichokes and green peas. Some fresh fish dishes are prepared with an indigenous wine, vernaccia di Sardegna. “We use vernaccia for everything. We drink it on ice as aperitif and then we cook everything in it, from lamb to fish.”

Another dish popular in seaports like Cagliari and Cabras is skate. But in Sardinia, it takes on a very different preparation. The chef says he will feature it as one of the daily specials soon because it’s a preparation best for summer weather.

“I cook the skate in water with onion and celery, and then chill it. Then I make a sauce with San Marzano tomatoes, onion, garlic, lemon and vinegar. When it has cooled to room temperature, I cover the skate with the sauce. Then we eat it cold the next day.”

Another specialty of the region is Bottarga di Muggine — salted, pressed and dried grey mullet roe. This ancient tradition has been kept by Sardinian fishermen from Castangia’s hometown, Cabras.

“It comes from a small bay, Stagno de Cabras, that has water that is both salty and sweet,” the chef noted. “This gives it a unique taste.”

 Bottarga di Muggine is served on salads, with simple pastas or thinly sliced on crostini with an olive paté, a curl of butter or simply drizzled with extra virgin olive oil. Castangia intends to feature this delicacy on the summer menu as well.

One more seafood preparation unique to the region is Sogliola alla Parmigiana. Castangia boils the sole, removes it from the stock and then dries off the fish completely. He melts sweet butter in a sauté pan, adds the fish and tops it with Parmesan cheese. The dish is finished on top of the stove.

Dinner is offered daily at Fabrizio’s Restaurant between 5:30 and 10 p.m. The official address is 806 Fourth St., but the easiest way to tell newcomeers how to find it is to look just to the north of the railroad crossing on Napa’s Soscol Avenue, south of Third Street. For information about Sardinian recipes and restaurant reservations, call 226-1900.