2 pounds white button mushrooms, stems trimmed and mushrooms quartered
2 tablespoons fresh lemon juice
5 tablespoons unsalted butter
1 tablespoon soy sauce
1/4 cup medium-dry sherry, such as Amontillado
1/2 cup heavy cream
1/4 cup chopped parsley
Freshly ground black pepper
Toss the mushrooms with the lemon juice. In a large skillet, melt 3 tablespoons of the butter. Add the mushrooms and season with salt. Cover and cook over moderate heat until the mushrooms release their liquid, about 4 minutes. Carefully pour the liquid into a small bowl; you should have about 1/2 cup.
Add the remaining 2 tablespoons of butter to the skillet and toss to coat the mushrooms. Cook, stirring a few times, until the mushrooms brown, about 4 minutes. Stir in the soy sauce, then add the sherry and cook over moderately high heat, scraping up the browned bits from the bottom of the skillet, about 1 minute. Add the cream and the reserved mushroom liquid and simmer over moderately high heat until thickened slightly, about 3 minutes. Stir in the parsley, season with salt and pepper and serve.