Sofrito is heavily emphasized as the third critical component in a "sofregit" base along with tomatoes and onions. Garlic is optional, as it is not considered an integral part of the standard "sofregit" recipe. Some "sofregit" recipes do not contain tomatoes at all, but are made more complex with the addition of diced vegetables such as leeks or bell peppers. In Italian cuisine, chopped onions, carrots and celery is battuto, and then, slowly cooked in olive oil, becomes "soffritto". It is used as the base for most pasta sauces, such as arrabbiata sauce, but occasionally it can be used as the
Tomato sauce of which is similar but of a thicker consistency. Tomato purée and tomato paste have FDA standards of identity (since 1939) for percentage of tomato solids, and generally do not contain seasonings other than salt; tomato sauce is nonstandardized. The second use of the term "tomato sauce" in the U.S. is for a cooked sauce of tomatoes, usually containing olive oil and garlic. This type of tomato sauce is generally served with pasta, and sometimes with meat. Less commonly, it is served with chicken or beef alone. One popular variety of tomato sauce is "marinara sauce, "an Italian-American term for