When I was a boy on Martha's Vineyard, spending my pre-summer-job summers in the water up to my neck, I often came home with a t-shirt wrapped around eight or ten hardshell clams that I had dug from the bottom with my feet.
We called them by their Native American name, quahaugs (pronounced "co-hogs"). My mother, Lucille Engley, always at least pretended to be happy to see seafood fresh from Vineyard Haven harbor. She usually made a chowder from the clams, with potatoes, onions, milk and rendered salt pork. That soup and her potato salad are still what I think of as her signature dishes.
Quahaug and fish chowder are also the signature dishes of Cape Cod and the islands of Martha's Vineyard and Nantucket, though clam chowder long ago outraced fish chowder as a favorite of tourists. (Fish chowder is not common in restaurants around the Cape, though a fine bowl of it can be found at Crabapple's here in Falmouth.)
Virtually every Cape Cod restaurant offers clam chowder, and most of it is not worth eating. At some point, tourists began to expect a chowder that is basically a thick cream sauce with a few soft potatoes and virtually no taste of clams. Clams have a fairly strong flavor, the taste of the ocean they came from. Which is, of course, the reason to eat clam chowder.
OK, enough preaching ...
LUCILLE'S QUAHAUG CHOWDER
12 large hardshell clams or 24 softshell "steamer" clams. (Do NOT use canned chopped clams.)
1/4 lb. salt pork, chopped into pieces the size of a pencil eraser (or 2 T. olive oil)
1 medium onion, chopped fine
2 stalks celery (optional)
2 large potatoes, cubed to the size of dice
1/2 cup water
1 cup half-and-half (or whole milk)
Salt and pepper
Shuck the clams (over a bowl so that you save the liquid from inside the clams) and chop the entire clam into pieces no bigger than a dime. Conserve the liquid. (If you use steamer clams, steam them open, save the liquid and chop the clams.)
Render the salt pork in a deep saucepan over medium heat. Cook it down until the pork pieces are crispy and brown. Set them aside. Saute the onion (and celery, if you're using it) until soft, then pour in reserved clam liquid and potatoes. If the potatoes aren't covered by the liquid, add enough plain water to cover. Cook until the potatoes are almost soft, then add the chopped clams and cook another few minutes. Check for seasoning and add salt and pepper to taste. The clams themselves are fairly salty, so be cautious with the salt. That's your chowder base. It can be made ahead and heated at mealtime, adding the half-and-half or milk just before serving. Re-heat the chowder once you've added the milk, but DO NOT BOIL. If you've used salt pork, you can sprinkle the cracklings into the soup.
Good luck and good eating.