pounds small quahogs or large cherrystone clams, if can not get fresh clams use canned.
slices bacon, cut crosswise into ½ inch strips
Tablespoons unsalted butter
medium Leeks, white and light green parts only, halved lengthwise and thinly sliced crosswise(2½ to 3 cups)
Cup finely chopped onions
Cup finely chopped celery
teaspoons minced garlic
sprigs fresh thyme
pounds potatoes, peeled and cut into ½ inch cubes(about 5 cups)
cups heavy cream
teaspoon freshly ground black pepper
teaspoons salt, to taste
Tablespoons cold unsalted butter, cut into half-tablespoon pieces
cup finely chopped fresh parsley
cup finely chopped fresh chives or green onions
In a large stockpot bring 3 cups of water to a boil. Add clams, cover, and cook for 5 minutes. Uncover the pot and quickly stir the clams with a wooden spoon. Cover and cook 5 to 10 minutes longer(this will depend on the type and size of the clams), or until most of clams are open. Transfer the clams to a large bowl or baking dish and strain the broth twice through a fine mesh sieve into a bowl, being careful to strain out the sand. (you should have about 8 cups of clam broth. If not, add enough water to bring the volume up to 8 cups.) When the clams are cool enough to handle, remove them from their shells and chop into 1/2 inch pieces. Set the clams and broth aside. Cook the bacon in a large heavy pot over medium heat until crisp and the fat is rendered. Pour off all the bacon fat except 2 tablespoons. Add 4 tablespoons butter, leeks, onions, and celery and cook until softened, about 5 min. Add garlic, thyme, and bay leaves and cook until the vegetables are thoroughly wilted, about 3 min., being careful not to brown. Add potatoes and reserved Clam broth and bring to a boil. Lower heat, cover, and simmer until broth thickens slightly and the potatoes are very tender, about 30min. (If you like thicker broth, mash some of the potatoes against the side of the pot with a wooden spoon.) Remove from the heat, stir in the clams and cream, and season with pepper and the salt to taste. Set the chowder aside for 1 hour, covered, to allow the flavors to marry. Place the pot over low heat and slowly reheat, being careful not to let boil. Serve hot; garnish each bowl with pat of butter and some parsley and chives.