There are almost as many ways to make clam chowder as there are cooks in New England. Here’s one that insists on salt pork for “true” flavor.
Fry salt pork in soup kettle until crisp. Remove with slotted spoon and set aside. Saute onions in fat until tender. Add stock, water, potatoes, and thyme. Simmer, partially covered, 15 minutes or until potatoes are just tender. Add half-and-half, clams, and reserved salt pork. Heat slowly. Do not boil.