French Onion Meatloaf Gruyère Indulge in this comforting, flavor-packed meatloaf made with juicy ground beef, caramelized onions, and rich Gruyère cheese—baked until perfectly golden for a hearty dinner classic. Ingredients 1 1/2 pounds ground beef 1 cup breadcrumbs 1/2 cup milk 2 large onions, thinly sliced 2 cloves garlic, minced 1 egg, beaten 2 tablespoons Worcestershire sauce 1 tablespoon Dijon mustard 1 teaspoon dried thyme 1/2 teaspoon salt 1/2 teaspoon black pepper 2 tablespoons butter 1/