Strain the clams over a bowl, reserving the liquid. With a sharp knife, finly chop the clams and set them aside. Cook the bacon in a skillet over med hi heat until crisp about 10 minutes. Using a slotted spoon, transfer the bacon to paper towels. Pour out all but 2b tablespoons of the fat from the skillet. saute the onion in the bacon fat until lightly browned. Simmer the potatoes in a lrg saucepan in the salted water until tender about 10 minutes.
Add the reserved clam liquid and bacon to the potatoes and there cooking liquid, and season with salt and pepper to taste. Simmer 5 minutes. add the half and half, bring to a boil, and add the clams. cook until they are barely heated through. taste and correct the seasoning. to each serving, add a dollop of butter, a pinch of thyme, and a sprinkle of fresh parsley