Food For Thought: Mighty Mirepoix

The vegetable foundation of everything

The first week of culinary school is not spent in front of a stove.  The first week is spent learning how not cut your fingers off or send your classmates to the burn ward.  Your accomplishments include holding a knife like a chef and figuring out the correct angle to hone your knife on a steel. 

You spend a lot of time learning your way around the various cuts of onion, carrot, and celery.  Pounds of each in fact.  The chef instructors are watching you, grading you, and definitely laughing at you.  But all the chopping isn’t for nothing - it’s a fundamental building block of learning to cook.

And all those pieces of onion, carrot, and celery find a use too. Those vegetables, sweated in fat (usually butter) in a roughly 2:1:1 ratio, form a building block of their own: mirepoix, the flavour base of so many French dishes. And because of French cuisine’s reach and influence those same building blocks are the foundation of far more dishes than you probably realize.

The name, like so many words in French cuisine, comes from a person, in this case Gaston-Pierre-Charles de Lévis-Lomagne, Duke of Lévis-Mirepoix, though the Duke himself likely had far less to do with it than did his chef. In fact, the story goes that the Duke was a rather incompetent fellow and his only real legacy is having his name attached to such an important component of French cuisine.

Mirepoix isn’t, by the way, the pieces of onion, carrot, and celery floating in your chicken noodle soup. Those are what we call the garniture, the vegetables we actually eat as part of the dish, and when served as a side dish themselves they are known as a matignon. Mirepoix is almost never eaten having given up all its flavour to the stocks, broths, and sauces that are the foundation of the recipe. By the time mirepoix is strained out it’s often bland and cooked to a virtual mush.

But why these three vegetables and how do they become so much more than their humble selves? The key to mirepoix is balance: aromatic onions and celery are balanced by the sweetness of carrot, each vegetable contributing its flavours and becoming even sweeter in the heat. How long they cook and whether they caramelize a great deal, a little, or not at all can transform the flavour of your recipe. Big chunks of vegetable suit longer cooking dishes, contributing their flavour more slowly. If your dish cooks quickly a smaller cut works better, but no matter the size it’s the even cuts that matter most - even cooking makes for even flavour.

You’ll get a fight from the French if you brown your mirepoix at all and if it’s not completely strained out, but not every cuisine thinks quite the same way. Other cuisines have versions of mirepoix that serve a similar purpose and give dishes their familiar and distinctive flavours. Sometimes they make their way into the final dish and other times not - it really depends.

Cooking something Chinese? A 2:1:1 ratio of green onion, garlic and ginger will give you a distinctive flavour that screams Asian cooking. Thai? Same ratio but with basil, ginger and lemongrass. Italians make a mirepoix too, except they call it soffrito and its sweated in olive oil. Of course, don’t confuse it with the sofrito of garlic, bell pepper, onion, and tomato common to many Spanish-speaking cultures, though depending where you are they may skip the tomato. German cuisine has suppengrün (quite literally “soup greens”) that is a mixture of leek, carrot, and celery root that form the basis of many soups and stocks. The Polish people have the delightfully-named włoszczyzna, meaning “Italian stuff”, though there really isn’t much that’s Italian about the combination of celery root, parsley root, carrots and leeks. Haitian cuisine wouldn’t be Haitian cuisine without epis, the fiery flavour base of Scotch bonnet peppers, garlic, and herbs. The celery, onion, and green bell pepper of Louisiana Creole and Cajun cuisine has a name that sums up its importance and transformative properties: the holy trinity.

But does it really matter though? Is it worth taking all the extra time and steps to cut and cook vegetables that way? It matters in the same way that browning meat before tossing it in a stew or using homemade stock matters. Mirepoix lends depth and personality to to a dish, making it a better version of itself. You can skip it if you want, but great cooking is rarely about shortcuts.

Once you understand how mirepoix and its cousins builds flavour you can learn how to layer flavours to suit your cooking. You’ll be able to look at a recipe and understand why certain ingredients are added at certain times and how changing them affects the final dish. Do as some cooks do and start first with the onions and carrots, adding your celery later and you can watch how the flavours develop differently. You can follow the rules or break them, or even create your own. Your food will taste like no one else’s.

Next time you’re cooking take the time to think about your mirepoix, or whatever flavour base you’re starting from. Take the time to build it correctly with proper, even cuts and a gentle heat. It’s part of the difference between being a okay cook and a great one - an appreciation of doing things the right way and not the quick way. Building flavour takes time, and the kind of flavour that mirepoix and its relatives contribute doesn’t come in a jar, a box, or a cube.