Tomato Sauce with Butter and Onion
Adapted from Marcella Hazan’s Essentials of Italian Cooking

Everything I could have possibly written for a headnote, has already been written above. The only two thing, and I mention one of them below, is this: do not, whatever you do (unless you are my friend Jane) throw away the onion after it is cooked. It is by far one of the most delicious things to eat, a great accompaniment to your pasta, or a decadent topping over generously buttered bread.

The other is that if you work with the tomatoes you, yourself, have prepared for a tomato sauce, your results are going to be that much more delicious. No canned tomato will ever rival a fresh tomato just fixed for a sauce.

2 pounds fresh, ripe tomatoes, prepared as described here or 1 (28-ounce; 800 grams) can quality whole tomatoes (I prefer Muir Glen), torn with your hands into small pieces with the tomato liquid
5 tablespoons (70 grams) unsalted butter
1 medium onion, peeled and halved
Salt, to taste
1 to 1 1/2 pounds pasta (I prefer buccatini here)
Freshly grated Parmigiano-Reggiano

Place either the prepared fresh tomatoes or the canned in 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 separates from the tomatoes and floats free. From time to time, stir with a wooden spoon, mashing any large pieces of tomato in the pan. Taste and adjust salt if needed. Hazan instructs you to discard the onion before eating, but I like to fish it out and serve it at our dinner on the side. Andrew and I fight for it: the onion mellows out, worn down by the acid in the tomato and the fat of the butter, and turns into something decadent and luxurious. Who knew a humble onion could have such beginnings?