In a large heavy pot cook the bacon until crisp and the fat is rendered, remove and set aside.
Add the onions and celery season with salt and pepper and cook until softened, about 5 minutes.
Add the garlic, thyme and bay leaves and crushed red pepper flakes, and cook until the vegetables are thoroughly wilted, about 3 minutes, being careful not to brown.
Add the flour and cook an additional 3 minutes.
Add clams with all the juice, and the potatoes and bring to a boil, simmer for 20 to 30 minutes or until the broth thickens slightly and the potatoes are very tender.
Reduce heat to low and stir in heavy cream add crush bacon and season with pepper and salt.
Cover, and Stirring often.
(If you like a thicker broth, mash some of the potatoes against the side of the pot with a wooden spoon.) Remove from the heat. (Do not allow to boil after adding the cream as it could break).
Set aside for 1 hour, covered, to allow the flavors to marry. Place the pot over low heat, and slowly reheat, being careful not to bring to the boil. Serve hot, garnished chives.