Vegetable stock can be used to impart a lightness and a delicate aromatic flavor to sauces. In traditional cooking it was primarily used as a poaching liquid for fish and sometimes calves’ brains. Contemporary chefs are using it more frequently in sauce making because of its delicacy, freshness, and ease of preparation. Vegetable stock is often an excellent substitute for fish stock when good-quality fresh fish or fish bones are unavailable.
Although the terms court-bouillon and nage are often used interchangeably, court-bouillon describes a broth from which the vegetables have been strained, whereas a nage is used for serving fish and shellfish à la nage—a style of presentation in which the fish is served surrounded by the poaching liquid containing the vegetables used in the court-bouillon cut into decorative shapes.
The technique for preparing court-bouillon depends on whether the chef wants the vegetables to release all their flavor into the surrounding liquid or prefers them to retain some of their flavor and texture (as in the preparation à la nage). To get the vegetables to release the most flavor into the surrounding liquid, they are best sweated in a small amount of butter or oil before being moistened. When preparing à la nage, where the vegetables will be served as an accompaniment, simmer them for 10 minutes in water before adding the wine and/or vinegar. (Acids slow the softening of vegetables in liquid.)
There are no hard and fast rules for which and how many vegetables should go into the stock; this decision depends largely on the final use of the stock. It is practically impossible to add too many leek greens or fennel branches, whereas too many carrots or onions (never use sweet onions for making stock) can make the stock too sweet, especially if it is going to be reduced for a sauce. Although traditional recipes call for a standard combination of vegetables to arrive at an anonymously flavored vegetable stock, contemporary chefs often prepare court-bouillon using only one or two vegetables to give a sauce a particular, subtle flavor. Court-bouillon made with leeks or fennel alone will give a delicate yet pronounced character to a sauce. Salt should be added to a vegetable stock only if the stock is to be used as is, without reduction.
The following recipe suggests the usual bouquet garni ingredients, but these too can be altered to give the stock a personal or regional character. Full-flavored herbs, such as oregano, marjoram, or lavender, should generally be avoided except under special circumstances—for example, for grilled fish surrounded by a court-bouillon-based sauce or for steamed crustaceans.
This recipe emphasizes the flavor of the stock rather than the integrity of the vegetables. If using vegetable stock as an accompaniment to fish or meats cooked à la nage, the vegetables should be cut carefully and evenly. Vegetable stock is best used the day it is made.
|red or yellow onions,
|garlic cloves, peeled|
|fennel branches, sectioned|
|olive oil or butter|
|large bouquet garni|
|dry white wine|
|good-quality white wine vinegar|
Copyright © 2017 by James Peterson. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.