"Prepare the night before, refrigerate overnight, and bake the morning of serving- easy!..."
INGREDIENTS
•
3 tablespoons salted butter, softened 12 slices white bread 1/2 cup (1 stick) butter, softened 8-ounces sliced fresh mushrooms 2 cups thinly sliced sweet onions 1 1/2 pounds Kielbasa sausage, sliced into bite-sized pieces 1 pound grated cheddar chees