A basic casserole includes a sauce, mix-ins (like noodles, rice, or protein), and a topping, such as cheese or buttered breadcrumbs. On every level you have options to make your favorite casserole a little healthier: use whole grains instead of simple carbs, focus on lean proteins instead fattier ones, use less cheese, spray the bread crumb topping with oil instead of dousing it in butter, make your own white sauce instead of buying the canned varieties.