They all look almost identical, but here's the one that I make, since it's one of my top 2 favorite clam chowders ever (the other one is Capt Parker's on Cape Cod).
Union Oyster House Clam Chowder
Makes 2 quarts
2oz salt pork
1 small onion, diced
1/2 cup butter
1/2 cup flour
2 ribs celery, minced
2 lbs fresh (or frozen) clams, diced
1 qt clam juice
1 lb potatoes, diced
2 cups Half & Half, warmed
salt, pepper, Tabasco, Worcestershire - to taste
Bring potatoes and clam juice to a boil; cook until potatoes are done, 10-15 minutes. Add clams (along with any surplus juice from same); cook 5 minutes. Set aside.
Note: do not overcook or clams will be tough.
Skin pork, dice and saute in pan; cook until rendered. Add onions; cook until glassy. Add butter, melt and cook slightly. Add flour. If mixture is too loose, add a little more flour. Cook until slightly tan colored.
Bring clams, juice and potatoes back to a boil. Add cooked roux. Thicken and bring to a rolling boil and stir. Add previously heated half & half to desired consistency. Season to taste.
Serve with oyster or pilot crackers.