A mirepoix (meer-reh-pwah) is a mixture of diced vegetables, such as onions, carrots, celery, parsnips and leeks, stewed in butter. Ham or belly of pork, a bay leaf and thyme are sometimes added. It forms the basis of many sauces, notably .

A mirepoix can also be added to pot roasts or braised meats.

A vegetable mirepoix (without the ham) is often used as a garnish for meat or fish dishes.