My recipe: I start with about four slices of bacon and fry it in a pot with chopped onions and celery. I cook it until the bacon, onions and celery are done and then add milk (A lot of folks use heavy cream). Bring it to a simmer If you're going to use potatoes, add diced potatoes at this point and simmer for about 20 minutes until the potatoes are done. Then add the clams and cook for about 5 minutes at a simmer. Mix a half cup of flour with a cup of cold water until it makes a paste. Slowly stir the paste into the soup and let it cook about five minutes. Add more or less of the paste to thicken as necessary. Add salt and pepper to taste.
I'm now a vegetarian, so I substitute about a half a stick of butter for the bacon.