MARCELLA’S TOMATO SAUCE WITH BUTTER AND ONIONS (for six)
2 cups canned imported Italian plum tomatoes, cut up, with their juice
5 tablespoons butter
1 medium onion, peeled and cut in half
1 pound penne
freshly grated Parmigiano Reggiano for the table
1. Put the canned tomatoes into a saucepan, add the butter, onion and salt, and cook uncovered at a very slow, but steady, simmer for 45 minutes, or until the fat floats free from the tomatoes. Stir from time to time, mashing any large pieces of tomato in the pan on the back of a wooden spoon. Taste and correct for salt. Discard the onion before tossing the sauce with the pasta.
NOTE: May be frozen when done. Discard onion before freezing.
from Marcella Hazan, Essentials of Classic Italian Cooking