Pesto Rosso

Cook's notes

The red cousin of basil pesto. Pesto just means pounded, and pesto rosso is the red version of the Genoese green one (pesto alla genovese). Most recipes use sun-dried tomatoes. Slow-roasted ones make a softer, sweeter, brighter pesto.

Almonds or pine nuts? Choose either under Nuts, above the ingredient list, and the list changes to match. Almonds give a coarser, toastier pesto and point it toward Sicily, where tomato-and-almond pesto alla trapanese comes from. Pine nuts make it softer and richer, closer to the Genoese original. They cost more and burn faster, so toast them over a watchful eye.

Make the tomatoes first. This uses slow-roasted tomatoes: about three hours in a low oven, but only fifteen minutes of your time. A single tray is enough for this pesto and a pasta dinner.

Turning a whole tray into pesto. One tray of slow-roasted tomatoes is twelve tomatoes, the way a box of romas is often sold, and that is exactly a triple batch. Choose 3× at the top and every amount changes to match. It makes about three cups, which is too much for a mini chopper: use a full-size food processor, or make it in two rounds. Freeze what you won't use this week.

On pasta. Stir the pesto into drained pasta off the heat with a splash of the pasta water, which loosens it into a sauce that coats. Never cook it in a hot pan; the cheese clumps and the basil goes dark. About a cup of pesto sauces a box of pasta.

Other ways to use it: spread it on a sandwich or a grilled cheese, spoon it over grilled chicken or a piece of salmon, swirl it into a bowl of soup or white beans, or stir it into ricotta for a dip.

Keeping it. Pack it into a jar, smooth the top, and pour on a thin layer of olive oil to keep air off it. It keeps in the fridge for up to five days. For longer, freeze it in an ice-cube tray, then move the cubes to a bag; they keep for about three months and thaw in minutes.