1 cup finely chopped onion
1 cup mushrooms, stems closely trimmed, thinly sliced
1/4 cup (1/2 stick) unsalted butter
1/4 cup sherry or dry red wine
2 large eggs
2 pounds ground sirloin
2 cups fine dry bread crumbs
1/2 cup finely chopped parsley
1 cup sour cream
1/2 teaspoon nutmeg

Sauté the onion and mushrooms briefly in butter until the mushrooms release their liquid. Add sherry or wine and continue cooking a few minutes more, until the mushrooms reabsorb the liquid. Cool.

Beat the eggs in a mixing bowl. Add the beef, bread crumbs, parsley, sour cream and nutmeg; mix well. Add the onion-mushroom mixture and blend. Place the mixture in an oiled or buttered 9 x 5 x 3-inch loaf pan. Bake at 350 degrees F for 1 hour or until firm and browned.

Serves 6 to 8.