Inspired by The Vegetarian Epicure, Book Two. Mutilated because I have no money.
1/2 cup apple juice
1/4 cup vinegar
1/2 stick butter
2 cloves garlic
red pepper flakes, pepper, cilantro to taste
peas, if you'd like
Brown mushrooms in the butter and garlic. Add the apple juice, spices, and vinegar and let cook down. Add peas. (I add them this late in the game because I don't want them to taste exactly like the mushrooms.)