A mirepoix ( meer-PWAH; French pronunciation: [miʁˈpwa]) is diced vegetables, cooked for a long time on a gentle heat without colour or browning, usually with butter or other fat or oil. It is not sautéed or otherwise hard cooked, the intention being to sweeten rather than caramelise. Further cooking, often with the addition of tomato purée, creates a darkened brown mixture called pincage. Where the flavour base is not pre-cooked the constituent vegetables may be cut to a larger size depending on the overall cooking time for the dish. Usually a mixture of onions, carrots, and celery (either common pascal celery or celeriac), the traditional ratio is two parts onions, one part carrots, and one part celery. Mirepoix is the flavor base for a wide variety of Western dishes, such as stocks, soups, stews, and sauces.
Similar flavor bases include the Italian soffritto, the Spanish sofrito, from Portuguese-speaking nations refogado (braised onions, garlic, and tomato), the German Suppengrün (leeks, carrots, and celeriac), the Polish włoszczyzna (leeks, carrots, celery root, and parsley root), the U.S. Cajun and Creole holy trinity (onions, celery, and bell peppers), and possibly the French duxelles (mushrooms and often onion or shallot and herbs, reduced to a paste).