Brunoise is a style of cutting vegetables into very small cubes, like a very fine dice. Brunoise is central to French cuisine, as vegetables cut in this way form the base of stocks used in many dishes.
A brunoise cut involves first julienning the vegetables — cutting them into thin strips — and then dicing the strips into even smaller cubes. Vegetables that are commonly cut in this way include carrots, celery, onions, turnips, and leeks. The chopped ingredients may be quickly boiled and cooled for use as a colorful garnish, or they may be browned in butter before water is added to make a flavorful broth.