If using larger, chowder-sized quahog clams, chop the meat finely.
Scrub:
Place the clams in a large soup pot and add:
Cover and steam over high heat until the clams open, 5 to 10 minutes. Transfer the clams to a bowl, discarding any that do not open (reserve the cooking liquid). Remove the clams from their shells, holding them over the bowl to catch any juices. Coarsely chop the clams and set aside. Line a fine-mesh sieve with several layers of cheesecloth and strain the cooking liquid from the pot and any juices from the bowl into a measuring cup. You should have about 4 cups; if there is less, add water, or more of the stock called for below.
Add to a soup pot over medium heat:
Cook, stirring occasionally, until browned and crispy. Using a slotted spoon, transfer the pork to paper towels to drain. Add to the pot:
Cook, stirring, until tender but not browned, 6 to 8 minutes. If desired, stir in:
Stir in the reserved cooking liquid along with:
Bring to a boil. Stir in:
Reduce the heat to a simmer and cook until the potatoes are tender, about 20 minutes. Stir in the chopped clams and reserved pork. Season with: