If using canned clams, drain off broth and set aside. If using fresh clams, scrub shells under running water and place in a steamer or large covered pot with 1 1/2 cups water to cover bottom. Cook gently over medium heat about 10 minutes or until shells open, stirring once or twice. Remove clams from pot and set aside to cool. Continue cooking broth until it is reduced in volume to about 1 1/2 cups; set aside. Remove clams from shells and cut into 1/8-inch pieces.
To make the chowder, place salt pork in a large pot over medium heat and cook until lightly browned, stirring occasionally. Remove pork with a slotted spoon and set aside. Add onions to drippings and cook until tender, about 5 minutes.
Return salt pork to pot and add reserved clam broth, potatoes, salt and TABASCO® Sauce. Simmer until potatoes are tender, about 20 to 25 minutes. Stir in clams, half-and-half, milk, and butter. Heat through, but do not boil.
Makes 8 to 12 servings.