In a large pot, cook the chopped bacon over medium heat until crisp. Remove bacon and set aside, leaving the drippings in the pot.

Add butter to the pot with bacon drippings. Sauté onion, celery, and garlic until soft, about 5 minutes.

Stir in flour and cook for 1 minute to remove the raw flour taste.

Gradually add clam juice and chicken broth, stirring continuously. Add potatoes, bay leaf, thyme, and black pepper. Bring to a boil, then reduce heat and simmer until potatoes are tender, about 15 minutes.

Stir in half and half and clams with their juice. Heat through but do not boil. Remove bay leaf before serving. Garnish with cooked bacon.