Cheese is the No. 1 thing I have missed the most on this diet. There are no good substitutes for the real thing, but sometimes you can trick yourself into thinking you're eating cheese! This recipe from Shmooed Food is a great cheat!
I made the recipe as written, accept for one change. Instead of using the cashews, I substituted a can of white beans. (I also tried using a can of chickpeas, but I preferred the white beans.) The consistency to a real cheese sauce was surprisingly close! The flavor of the nutritional yeast is pretty strong, so be prepared for that!