tomato sauce <ref>if you don't have tomato sauce you can use unseasoned stewed tomatoes

Tomato sauce is a cooked preparation of tomatoes, typically sieved or blended to achieve a smooth, pourable consistency, and seasoned with salt, garlic, herbs, and sometimes oil. It originated in Mediterranean cuisine following the introduction of tomatoes to Europe from the Americas in the 16th century, and became fundamental to Italian cooking by the 17th century. The ingredient consists primarily of tomato solids and juice reduced through simmering, which concentrates flavor and develops depth through the Maillard reaction. Quality tomato sauce may be made from fresh tomatoes in season or from canned or preserved tomatoes year-round, with variations ranging from simple, minimally seasoned versions to complex preparations incorporating onion, garlic, olive oil, and regional herbs such as basil, oregano, or bay leaf.

Tomato sauce serves as a foundational ingredient across numerous cuisines, most prominently in Italian cooking where it accompanies pasta, risotto, and polenta, and in Mediterranean, Spanish, and Latin American traditions. It functions as a cooking medium (braising meats or vegetables), a sauce base for soups and stews, and a coating component for baked dishes such as lasagna and moussaka. The sauce may be used as-is or further reduced and concentrated to intensify flavors, or enriched with cream, meat stock, or additional aromatics depending on the dish requirements. Its acidity balances rich proteins and fats, while its umami qualities enhance savory preparations.