Clam Chowder

I got this recipe years ago from my awesome mother in law. It is delicious! Thick and rich and yummy. Perfect for a cool night. (Don't mind that it's almost summer...just save it for later ;)

2 6 ounce cans minced clams
1 cup onion, finely chopped
1 cup celery, finely chopped
2 cups potatoes, chopped
3/4 cup butter
3/4 cup flour
1 quart Half & Half
2 tsp salt
1/2 tsp sugar

Drain juice from clams and pour over vegetables in a medium saucepan. Add enough water to barely cover the vegetables. Cover and simmer until potatoes are tender--about 15 minutes. In the meantime, melt butter and add the flour. Stir until smooth to make a roux. Add cream and cook, stirring constantly until smooth and thick. Pour cream mixture over vegetables, add clams and heat through. Season with salt, sugar. Add pepper to taste.