Melt 1/4 cup butter in a large skillet; add livers and mushrooms. Cook over medium heat, stirring occasionally, 30 minutes or until liquid is absorbed.
Add liver mixture to White Sauce; stir well. Spoon into center of a warm serving platter; keep warm.
Combine eggs, whipping cream, salt, and pepper; beat well with a wire whisk.
Melt remaining butter in a large skillet over medium heat; add egg mixture. Cook over medium heat, stirring occasionally, until eggs are set. Spoon eggs around liver mixture on serving platter; garnish with parsley. Serve immediately.