Ingredients
2 cups canned plum tomatoes (whole, peeled, chopped, with their juices about one 28-oz. can)
5 tablespoons unsalted butter
1 medium yellow onion, peeled and cut in half
salt, to taste
Preparation
#1 Combine the tomatoes, their juices, the butter, and the onion halves in a medium saucepan.
#2 Add a pinch or two of salt. Place over medium heat and bring to a simmer. Cook, uncovered, at a very slow but steady simmer, adjusting the heat as necessary, for about 45 minutes, or until droplets of fat float free from the tomato.
#3 Stir occasionally, mashing any large pieces of tomato with the back of a wooden spoon. Taste and salt as needed.
#4 Discard the onion.
