What is the essential mixture of coarsely chopped onions, carrots, and celery used in stock preparation called?

The essential mixture of coarsely chopped onions, carrots, and celery used in stock preparation is called mirepoix. This combination serves as a flavor base for a variety of dishes, particularly stocks, soups, and sauces. The proportions of the vegetables typically follow a ratio of 2 parts onion to 1 part each of carrot and celery, although variations can occur based on regional preferences and the specific dish being prepared.

Mirepoix is foundational in culinary practice because it provides depth and complexity to the flavor profile of the final dish. The cooking process helps to release the natural sweetness of the vegetables, enhancing the overall taste.

Other terms mentioned, such as brunoise, refer to a specific way of cutting vegetables into small dice rather than a mixture used for flavoring. Roux is a thickening agent made from flour and fat, and fondo refers to the flavorful base often created from simmering meat, bones, and vegetables, but does not specifically identify the vegetable mixture used in stock preparation.