Reduce 1 cup (250 milliliters) white wine with 2 finely chopped shallots until only 2 tablespoons (30 milliliters) liquid remain. Let the reduction cool (do not strain it), then work it into 7 ounces (200 grams) creamed butter. Add 1 tablespoon (15 milliliters) chopped parsley and 2 teaspoons (10 milliliters) lemon juice. Season with salt and pepper. Older recipes incorporate diced and poached marrow into the butter along with the other ingredients. The only difference between a Bercy Butter without marrow and a shallot butter is that the Bercy Butter is flavored with reduced white wine. Season with ½ teaspoon (2 milliliters) salt.