Mushroom Sauce is simply a combination of reduced mushroom essence and demi-glace or glace de viande and butter.
This sauce can be used as a model for sauces based on a wide variety of wild mushrooms. The mushrooms are first cooked in a small amount of water or stock, which then becomes the basis for the sauce. The cooked mushrooms are reserved and added at the end. Although the foregoing recipes call for whole button mushrooms, leaving the mushrooms whole is impractical with large wild mushrooms such as Boletus edulis (cèpes/porcini). It is, of course, acceptable to slice or cube the mushrooms.
The flavor of mushrooms can be made more assertive by first sautéing them in hot olive oil, goose fat, or butter until they brown. Some recipes call for sprinkling the mushrooms with chopped shallots, chopped garlic, or persillade.
Copyright © 2017 by James Peterson. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.