Have you tried a cheesy baked cauliflower in place of traditional mac and cheese? You also don't really need the flour roux for the sauce, you can just as easily make a simple creamy cheese sauce over a double boiler with some heavy cream, some freshly grated cheeses of choice (I would strongly recommend using something that melts better such as muenster in addition to the cheddar. Cheddar alone, especially sharp cheddar, separates easily) some mustard powder, and a few dashes of hot sauce. Some people say to even throw in a slice or two of plain old processed american cheese, since it also helps with preventing the cheese from separating. You could even make it more like a meal by throwing in some diced ham or some diced grilled chicken. You could toss the whole thing under the broiler a bit to brown the top, but there's not really any need to bake the whole thing in the oven for an hour like the traditional recipe.