I could no longer resist this sauce, and frankly, I don’t know why I even tried to: food bloggers obsess over it, and they’re not a bad lot to base a recipe selection upon. Adam of Amateur Gourmet fell for it five years ago. Molly at Orangette raved about it over two years ago, with a bonus approval marking from Luisa at Wednesday Chef. Then Rachel Eats fawned over it too, and Rachel, you see, she lives in Rome right now — I want to be in Rome right now — Rome, where you can get authentic, perfect tomato sauce a zillion places every single day. And yet she stayed in and made this one. That sealed the deal.
So what is it with this sauce that it moves people to essays over it, tossing about exclamations like “brilliant!” and “va-va-voom” and promises that “something almost magical happens”? Is it garlic, a slip of red pepper flakes, a glug of red wine or a base of mulched carrots, onion and celery, as so many of us swear by in our best sauce efforts? Is it a spoonful of tomato paste or a pinch of sugar? Is it the best olive oil money can buy? It is none of these things, not a single one: It is butter. And an halved onion, cooked slowly as the sauce plops and glurps on the stove, thendiscarded when it is done.
Butter and the juice of stewed onion is all it apparently takes to transform a two-pound can of tomatoes to something velvety and lush. It manages to remind you of how fresh and sweet tomatoes are in the summer, but more fitting for the winter when canned tomatoes are the order of the day.
Another thing that blew my mind about this sauce: I, for one, am a grated parmesan junkie. I not only sprinkle it over my bowl of pasta, I like to have additional nearby, to apply a fresh coat to the layers of pasta that follow. So you can imagine my shock to find that I liked this dish even more without the parmesan. The flavor of the sauce is so delicate, fresh and sweet that it needed nothing at all.
Serves 4 as a main course; makes enough sauce to lightly coat most of a pound of spaghetti
28 ounces (800 grams) whole peeled tomatoes from a can (San Marzano, if you can find them)*
5 tablespoons (70 grams) unsalted butter
1 medium-sized yellow onion, peeled and halved
Salt to taste
Put the tomatoes, onion and butter in a heavy saucepan (it fit just right in a 3-quart) over medium heat. Bring the sauce to a simmer then lower the heat to keep the sauce at a slow, steady simmer for about 45 minutes, or until droplets of fat float free of the tomatoes. Stir occasionally, crushing the tomatoes against the side of the pot with a wooden spoon. Remove from heat, discard the onion, add salt to taste (you might find, as I did, that your tomatoes came salted and that you didn’t need to add more) and keep warm while you prepare your pasta.
Serve with spaghetti, with or without grated parmesan cheese to pass.