For a homemade twist on this classic recipe, you can make your own mushroom sauce by sautéing sliced mushrooms and onions in butter and flour, then adding milk and broth to create a creamy sauce. You can also add additional toppings like sliced almonds or breadcrumbs for extra crunch. If you want to save time, you can prepare the casserole a day ahead and store it in the fridge until ready to bake.
