Boston Clam Chowder

2 6 ounce cans of minced clams
1 cup chopped onion
1 cup fine chopped celery
2 cups fine diced potatoes
3/4 cup butter
3/4 cup flour
1 quart half & half cream
1 1/2 teaspoon salt
few grains pepper
1/2 teaspoon sugar

Drain juice from clams and pour over vegetables in medium pan.  Add enough water to barely cover and simmer covered over medium heat until potatoes are tender.  (about 20 minutes). In the meantime, melt butter, add flour and blend.  Cook a minute or 2.  Add cream, cook, and stir until smooth and thick, using wire whisk to blend.  Add undrained vegetables and clams, and heat through.  Season with salt and pepper to taste.