A good friend of mine once went on a date with a middling restaurant chef who, when they went back to his place at the end of the night, started to whip up a small batch of this sauce, telling her that it was his own creation. As she watched him pour a can of tomatoes into a pot, followed by some cold butter and raw onion, she asked if he knew who Marcella Hazan was. It wasn't long before his face was the color of marinara.
The original recipe, called Tomato Sauce III, can be found in Hazan's formative "The Classic Italian Cookbook," from 1987. (The book was originally published in 1973.) It's all of four ingredients, and, especially if you make it with canned tomatoes, involves virtually no prep and takes well under an hour to make, but tastes like it took all day. Famously, it involves an entire stick of butter and an uncooked onion. The butter adds richness, of course, while the onion* lends its depth and, as it loses its integrity, turns soft and silky, enhancing the tomatoes' sweetness.
A couple of years ago, I was having lunch with a friend who knew Hazan's husband, Victor, her longtime taste-tester and translator. I asked her to ask him how the sauce came to be. She emailed me Victor's response:
"That sauce of Marcella's travels the world. As you may remember, Marcella comes from a fishing and agricultural town in Romagna, the coastal area of Emilia-Romagna. When they cook tomatoes for sauce, they use butter and onions. The usual practice is to mince the onion and to soften it in butter over the stove, then to add tomatoes. Her mother used fresh plum tomatoes in season, and tinned tomatoes otherwise. When Marcella came to New York after we married, she discovered a love for ingredients, and found many ways to allow them to express their character. She remembered her mother's old sauce of sautéed minced onion, butter and tomatoes, but she transformed it into the version that so many have adopted as their basic tomato sauce. The onion is used whole, it is not sautéed, its sweetness develops slowly and envelops the tomatoes."
Victor closed the email in what I'm told is his characteristic affection for his late wife, and poise in prose: "In one sense it is a traditional sauce out of her background, in another it's an improvisation generated by her unquestioned genius for cooking."
*This recipe suggests you discard the onion after all of its flavor has melted into the sauce, but I am here to tell you not to throw it away! Either puree it into the tomatoes with a stick blender or pluck it out of the pot and spread it on a slice of crusty bread: A cook's spoils never tasted so good.
I'm going to let you all in on a little secret. (It's one I'm especially embarrassed to tell Jim Webster, one of my editors, who makes and cans fresh tomato sauce every summer.) I have only made Marcella's sauce with fresh tomatoes once in my life. Every other time – there were dozens at least – I've used canned tomatoes. (Of course, if you have a bumper crop of tomatoes and love the process of canning, don't let me stop you!)
Think of this as a rich marinara and the possibilities for turning it into dinner become endless: Pizza, bruschetta, over gnocchi or layered in a lasagna or parmigiana. Thanks to that stick of butter, it's really lovely with pasta, especially if you reserve some of the pasta water to help emulsify the sauce, turning it creamy and yet bright, and bursting with the freshness of summer tomatoes.