I'm a subscriber of the idea the cooking is a labor of love, not just of the craft but a love of good food. For instance, I learned to make beer because I like good beer. To learn to cook, one first has to learn to taste. Going back to beer, I taste every type of grain that I use before I crush it. That way I can get an idea what the finnished product will taste like. When I'm cooking an ingredient that I'm not familiar with, I taste it raw. The point that I'm trying to make is to teach your student to taste what they're making and make things that they enjoy eating. Often times, if somebody can see how simple something that they like is to cook, they're more likely to explore dishes they have never tried. I'm sure that you could steal borrow from some of the cooking shows and make games out of it. Think surviver, only you don't get rid of anybody, you reward the winning team/cooks.