Mirepoix (cuisine)
These three ingredients are commonly referred to as aromatics. Similar such combinations, both in and out of the French culinary repertoire, sometimes include leeks, parsnips, garlic, tomatoes, shallots, mushrooms, bell peppers, chilies, and ginger. For the combination mirepoix au gras, or a Matignon, ham or pork belly are used as additional ingredients. In Cajun cuisine, a mirepoix or trinity is a combination of onions, celery and bell peppers.