Casseroles are beautiful. They are complete meals in themselves, and they are quite versatile in that you can use any ingredient you like. The thing with casseroles, though, is it's so easy to go crazy in making them that you forget to ensure that each serving portion is healthy for you to eat and not loaded with calories. This quinoa and sweet potato casserole is the perfect casserole for the health-conscious dieter. It looks and tastes gorgeous, but it won't bust your waistline.