Editor’s Note: This recipe for an everyday passata is excerpted from The Food of Sicily by Fabrizia Lanza (Artisan Books). Copyright © 2023. Photographs by Guy Ambrosino. A classic pantry staple, this tomato sauce is the best way to preserve summer’s bounty through the lean winter months. 

The idea of getting through winter without homemade tomato sauce is unheard of for most Sicilian households, so the end of August is a busy time as everyone makes big batches of salsa pronta that can be stored for the year. Since it is so often used as an ingredient that may be cooked further in a recipe, a good salsa pronta should be smooth, light, and fresh, not cooked to a paste. Cooks usually start with ripe San Marzano or Roma tomatoes, which are prized for their dense, pulpy flesh and rich flavor. Adding a simple pesto of basil and garlic and olive oil for the last bit of cooking keeps the sauce bright.

SALSA PRONTA 

Makes about 4 liters (4 quarts) 

INGREDIENTS

• 8 pounds (3.6 kg) Roma tomatoes
• 1 1/2 cups (360 ml) water
• 3 large red onions, coarsely chopped
• 6 garlic cloves, peeled and left whole
• 4 bay leaves, preferably fresh
• Leaves from 2 large bunches of basil
• 3/4 cup (180 ml) olive oil
• 1 tablespoon fine sea salt, or to taste
• 1 tablespoon sugar, or to taste

PREPARATION

1. In a large heavy pot, combine the tomatoes, water, half of the red onions, half of the garlic cloves, and all of the bay leaves. Bring to a boil over medium-high heat, then reduce the heat, cover, and simmer until the tomatoes split, begin to break up, and eventually become a rough puree, about 40 minutes. Make sure to stir the tomatoes occasionally to keep them from sticking, and mash them gently against the side of the pot to help them break down. When the tomatoes are tender, remove the pot from the heat and let cool slightly.
2. Set a food mill over a clean pot. Pass the tomato mixture through the mill to separate the skins and pulp. Discard the skins.
3. In a food processor, combine the basil leaves and the remaining chopped onion and garlic cloves and pulse until finely chopped.
4. Add to the pot of tomatoes, along with the olive oil. Bring to a boil, then reduce the heat and simmer, uncovered, until the mixture has thickened slightly, about 30 minutes. Remove from the heat and stir in the salt and sugar.

NOTE: The sauce can be used right away or bottled or frozen for later use. Sauce that has been safely processed will keep for up to 1 year stored in a cool, dark place. (For more information on canning, visit the website of the National Center for Home Food Preservation at nchfp.uga.edu.) Frozen sauce will keep for up to 3 months.