The Italian name for the classic base of chopped onion, carrot, and celery is soffritto.
In Italian cooking, these vegetables are gently cooked in olive oil, butter, or another fat until softened and lightly colored. The resulting soffritto builds a savory foundation for dishes such as ragù, soups, risotto, braises, and stews. Its name is related to the Italian verb soffriggere, meaning to fry gently or lightly.
The raw chopped mixture is sometimes called battuto, especially before it is cooked. Once the vegetables have been softened in fat, the preparation is generally described as soffritto. Recipes may expand the basic combination with garlic, parsley, shallot, or leek, depending on the region and dish.
Soffritto is related to—but not identical with—the French mirepoix. Mirepoix traditionally uses onion, carrot, and celery in a roughly 2:1:1 ratio and is usually cooked without browning. Italian soffritto often involves olive oil and may be cooked further, producing deeper flavor and color. The Spanish sofrito is another related flavor base, but commonly includes tomato and garlic.