Mirepoix

...

Mirepoix is a combination of onion, carrot and celery (both Pascal & celeriac) vegetables, and are used as a base to create soup stocks, stews and a wide variety of other meals or garnishes. Onions, carrots, celery, leeks, parsnips, garlic, tomatoes, shallots, mushrooms, peppers and ginger are among a group of vegetables commonly referred to as aromatics. They may also be added to produce variations of a Mirepoix. Mirepoix is the French term and it is sometimes referred to as the “French Holy Trinity.” Other countries have their own blend of vegetables and spices. In Italy, for example, the base is referred to as Soffritto, in Portugal, Refogado. In the American South, specifically in Cajon or Creole cuisine, the Mirepoix is referred to as the Cajun Trinity (or just Trinity), with a variation of vegetables. Within France itself, depending on the region, variations from the Classic Mirepoix exist. National cuisines are often built upon a small group of familiar flavors used in a wide variety of creative ways.

In its Classic form, Mirepoix consists of onions, celery or celeriac and carrots. The correct ratio of these vegetables, by weight and not volume, is 2 parts onion, 1 part celery and 1 part carrot. Vegetables are diced or minced as evenly as possible, and are heated before other ingredients are added – creating a rich flavor which further develops as the dish is cooked. Some cooks add herbs to their Mirepoix, and it is also possible to see finely cubed fatty cuts of meat, such as bacon, which will brown and crisp in the pan.

A slow and low heat cooking method, also referred to as “sweating” the vegetables, tenderizes them. A sautéing method, which uses a medium-high heat, in addition to tenderizing, releases their natural sugars, allowing them to develop a complex caramelized flavor. A wonderful and varied mix of aromas and flavors develop as the vegetables are softened and/or browned. These flavors are incorporated into the finished dish or meal. In addition to being used at the beginning, Mirepoix may also be added into a side dish at the end to enhance or add flavors – to boiled or mashed potatoes or meats, for example.

Usually, especially in European cooking, flavorful base mixtures are gently "sweated" before liquids are added. The distinction between sweating and sautéing is an important one, because sautéing, with its emphasis on high heat and rapid cooking, is designed to seal the flavor of the vegetables within the vegetables, while sweating, which is cooking over low heat, is designed to get the vegetables to release their flavor so that it ultimately ends up in the surrounding liquid.

Traditional directions for sweating vegetables call for covering the pan so the moisture and aroma from the vegetables is entrapped and the vegetables don't have a chance to brown. But for some dishes, it's useful to first cook the vegetables gently (covered), and then remove the lid and allow the vegetables to slowly caramelize before adding liquid. This caramelizing gives soups and sauces a richer and more complex flavor and a deeper color.

Cutting Vegetables for a Mirepoix

For stocks, Mirepoix is eventually strained from the finished stock, so it's not critical to use great precision when chopping the vegetables. The pieces, however, should be more or less uniform in size, to allow for equal cooking times between differing vegetables.

The more finely vegetables are chopped, the more quickly their flavors and aromas are released into a stock.
For white stock, a ½ inch dice is common. Since brown stock is always simmered longer than white stock, it's acceptable to cut the Mirepoix into larger, 1-inch pieces. Mirepoix for a pot of long-simmering stock (4 hours) can consist of very large pieces of vegetables—onions cut in half, whole celery ribs, and carrots in chunks.

Fine dice for a quick-cooking sauce.

For dishes, the size individual vegetables are cut depends on how long the mixture will cook. The French deem it important that a classic Mirepoix be cut into very tiny dice called brunoise, since the smaller pieces will release their flavor more quickly during the short cooking time.

A medium cut for soups and braises.

Chunks for long-cooking stews.

Other cuisines call for mincing aromatics – like ginger and lemongrass, which are too fibrous to eat in large bites but, for a long-simmering dish, those aromatics may be left whole or slightly crushed, and then removed after cooking. Size also affects the appearance of a dish. If making a light sauce which is not pureed, cut the aromatics in small, neat pieces for a final, attractive presentation.

Preparing a Mirepoix

To achieve the best flavor from Mirepoix, thoroughly rinse and trim all the vegetable, first. Onion skin will impart an orange or yellow tint to a simmering liquid, which may not be desirable. Additionally, peel the very top layer from onions, to insure that bruises and/or rot are removed. I peel all vegetables on the premise that flavor is extracted into the dish more evenly.

Step 1

Start by cooking onions or leeks in a layer of fat – just enough to coat the bottom of the pan and vegetables. When the onions begin to release their juices and become slightly translucent, add the carrots and then after 1 or 2 more minutes add the celery.

White stocks and cream soups require cooking the Mirepoix in fat over low heat, until juices are released – also referred to as sweating. This can take up to 10-20 minutes. If the pan or pot is covered, it is called smothering. Mirepoix can also be cooked until the vegetables turn a deep, rich brown, either on the stove or in the oven – also referred to as caramelizing.

Step 2

For additional flavor, and if the recipe calls for, add tomato paste or purée after the vegetables are partially cooked and the celery is softened.

Step 3

Cook carefully with constant attention and stirring, until the mixture is a deep, rusty brown and the Mirepoix has a sweet aroma. This technique is called pinçage, stemming from the French pincer, “to stiffen or pinch.”

Mirepoix Base Variations

Classic Mirepoix – France
     a. Name: Mirepoix
     b. Cooking Fat: Butter
     c. White Onion: 2 parts, diced
     d. Celery: 1 part, diced
     e. Carrot: 1 part, diced
     f. Herbs & Spices (optional): thyme & bay leaf
Used to flavor a variety of stocks and soups. Often, tomato puree or paste is added to make brown stock.

White Mirepoix – France
     a. Name: Mirepoix
     b. Cooking Fat: Butter
     c. White Onion or White of Leak: 2 parts, diced
     d. Celery Root or Hearts: 1 part, diced
     e. Parsnip: 1 part, diced
Used to flavor white stocks and soups that require a milder than Classic Mirepoix flavor and/or ivory and white color.

Gascony Mirepoix – France
     a. Name: Mirepoix
     b. Cooking Fat: Duck, Goose or Pork
     c. White Onion: 2 parts, diced
     d. Celery: 1 part, diced
     e. Carrot: 1 part, diced
     f. Meat: Confit of Duck or Goose, Bayonne ham
     g. Herbs & Spices (optional): thyme, bay leaf

Provence Mirepoix – France
     a. Name: Mirepoix
     b. Cooking Fat: Olive Oil
     c. White Onions: diced
     d. Leaks: diced
     e. Garlic: sliced
     f. Tomatoes: diced
     g. Celery: diced
     h. Carrot: diced
     i. Meat: Usually none
     j. Herbs & Spices: thyme, bay leaf, orange zest, saffron

Soffritto – Italy
     a. Name: Soffritto
     b. Cooking Fat: Olive Oil, Butter, rendered Prosciutto or Pancetta Fat
     c. White Onions
     d. Garlic
     e. Fennel
     f. Meat: Prosciutto, Pancetta or Veal
     g. Herbs & Spices: parsley, bay leaf and sage

Cajon Trinity – American South
     a. White Onion: 2 parts, diced (1 cup) – 50%
     b. Celery: 1 part, diced (½ cup) – 25%
     c. Bell Pepper-Green: 1 part, diced (½ cup) – 25%
Used in many Louisiana Creole and Cajun Dishes.

Matignon – Edible Mirepoix
     3 ½ oz. ham
     4 ½ oz. onion
     4 ½ oz. carrot
     2 oz. celery
     1 sprig thyme
     1 bay leaf
Sometimes referred to as “Edible Mirepoix,” mushrooms and assorted herbs and spices are added, as desired. It is also used to garnish a main dish, as well as to flavor it.
...