Nacho cheese sauce has a permanent place at stadiums and movie theaters for the obvious reason that its a surefire crowd-pleaser that sells, sells, sells. Statistically speaking, the odds are very good that if you have opposable thumbs and can easily digest lactose, you also love nacho cheese sauce. This recipe is based on bchamel, one of the so-called mother sauces of classical french cuisine and the base for dishes like mac and cheese, lasagna, and pommes dauphinoise. You didnt expect nacho cheese to be quite so sophisticated, did you?This sauce is quite simple to make. Just dont overcook it, because it may thicken too much and separate. If youre in doubt about the texture, err on the side of thin by whisking in a little hot water until you reach the desired viscosity. You don't want a gloppy sauce. This is a fabulous dish to make for parties and potlucks, as long as it can be kept warm throughout service. Because its so quick and easy, it also makes a lovely weeknight treat. Keep it healthy with additions like grilled chicken and black beans, or indulge by slathering it on homemade french fries. You can even use it as a veggie dip, which might just sell your stubborn carb-addicted children on those carrots and broccoli you're always pushing.