My copy of Marcella Hazan's The Essentials of Italian Cooking is as dog-eared and stained as my copy of Pride and Prejudice. And it practically opens itself to the page for butter, onion and tomato sauce. I first made this recipe over 20 years ago and to this day still can't believe the sweet flavor created from simmering canned tomatoes with butter and onion in for a mere 45 minutes. I have also found that the flavor of the sauce changes and am sharing my favorite brands of canned tomato and butter I use. This is one to bookmark, my friend!
In a blender or with a stick blender, blend tomatoes to desired consistency. I prefer my sauce smoother. You certainly can leave them whole and crush them right in the pan with the back of a wooden spoon.
1 28 oz can whole, peeled Italian tomatoes
Peel onion, cut in half, trim shaggy roots and add to the pan.
1 yellow onion
Add the butter a little salt and pepper (about 1 tsp of salt and maybe 1/2 tsp of pepper to start).
5 tbsp unsalted butter, salt and pepper
Simmer for 45 minutes uncovered until the fat starts to separate from the tomatoes.
Adjust seasonings with salt and pepper.
Notes
Options: If desired, add crushed red pepper or fresh basil but keep it simple. This is a delicate sauce and barely needs parmesan (but I usually add it).Make ahead: Make this sauce a day or two ahead of when you plan to serve it. It'll keep in the fridge for up to 4 days.Freezing Tips: Allow the sauce to completely cool before storing in a freezer safe container or ziploc bag. Can freeze for up to 3 months. Defrost in the fridge or microwave before heating.