1/4 lb. butter
3 tbsp. finely chopped onion
3 tbsp. finely chopped carrot
3 tbsp. finely chopped celery
2 1/2 c. canned Italian tomatoes with their juice
1/4 tsp. sugar
1/2 c. heavy cream

1. Put all the ingredients except the heavy cream in a saucepan and cook at the merest simmer for one hour, uncovered. Stir from time to time with a wooden spoon.

2. Puree the contents of the pan through a food milk (you can prepare the sauce up this point ahead of time, and refrigerate it for a few days or freeze it) into a saucepan and bring to a simmer, stirring with a wooden spoon. Add the heavy cream and stir-cook for one minute more. Use immediately.