Cook bacon until brown and crispy. Transfer to a paper towel-lined plate.

Saute onion in bacon fat and butter in the stockpot. until onions have become translucent, about 2-3 minutes. 

Drain clams, reserving clam juice and set aside

Whisk in flour until lightly browned, about 1 minute. Gradually whisk in bottled clam juice and reserved clam juice whisking constantly until slightly thickened about 1-2 minutes. 

Stir in potatoes.  If you need additional liquid to cover potatoes, you can add a cup of chicken or vegetable broth

Simmer until potatoes are tender, about 12-15 minutes.*

Stir in half and half and clams until heated through, about 1-2 minutes; season with salt and pepper, to taste. If the soup is too thick, add more half and half as needed until desired consistency is reached.

Serve immediately, garnished with bacon.