This dish is so easy to make, yet tastes like you've been slaving away for hours over the stove. You can be creative in your choice of cheese, combining two, three, or even four different cheeses, as long as they're capable of melting into a sauce. You can also add a handful of cooked vegetables, if you like - in fact, this is a GREAT use for leftover veggies! A few tips: be sure to remove the sauce from the heat before adding the cheese, as heating cheese too quickly will cause it to separate. Also, hold back on the salt until after you've added the cheese to the sauce - the variety of cheeses you use will greatly affect how much seasoning you'll need to add.