Macaroni casserole is a baked macaroni dish. It is especially known as a staple in northern European home cooking. It is a dish of cooked macaroni and a mixture of egg and milk with additional ingredients like meats, vegetables or fish. It is commonly made with cheese and/or breadcrumbs sprinkled on top.The dish is reminiscent of frittata, with the main difference being that it is baked entirely in the oven. It is usually eaten with ketchup.