If you have any suspicions that your clams will have some sand in them, soak them in water for at least an hour before cooking.

In a large pot, lightly brown a clove of garlic or two in some olive oil. Remove the garlic clove and add the clams, along with a splash of white wine. Cover immediately (depending on the heat, the wine may cause the oil to spatter) and cook over a lively flame until all of the clams have opened. Remove the clams and remove the meat from their shells. (If you like, you can leave a few clams in their shells for decorating your final dish.) If your clams are large, cut them up roughly. Keep the juices in the pot for later.

Meanwhile, make a soffritto of finely chopped parsley and another clove or two of garlic gently sautéed in a generous amount of olive oil. Add the canned tomatoes and simmer for a few minutes to let the flavors meld.

Add the fish stock or water to the tomato sauce, along with your fregola and the juices from the clams. Raise the heat until you have reached a low boil. It will seem as first as if you have way too much liquid, but not to worry: fregola absorbs a lot of liquid. You will soon see that the fregola will have absorbed most, if not all, of the liquid. In fact, you will probably need to add water from time to time; the fregola should be covered with liquid until it is almost done; then let it cook down to your taste (see Notes). Cooking time will vary, but count on 20 minutes or more.

When the fregola are al dente, add the shelled clams to the pot, just long enough to heat them through. Ladle the fregola and accompanying sauce into deep pasta plates, top with reserved clams in their shells, a bit of finely chopped parsley and un filo d'olio (a drizzle of olive oil). Some freshly ground pepper would not be amiss, either.