Mirepoix

A mixture of diced carrots, onions, celery, and herbs sauteed in butter. Sometimes ham or bacon is included. Mirepoix is used to season sauces, soups, and stews as well as for a bed on which to braise foods (meats or fish). A white mirepoix for light-colored dishes substitutes the white part of leeks for the carrots. An Italian version, soffritto, usually consists of onions, carrots, and celery sauteed in olive oil in place of butter.