This dish is from the great book Beyond the Great Wall: Recipes and Travels in Other China. Many of the recipes are super simple, including this one.
Here's how to make it: Boil some potatoes until they are juuust soft, cut them up and throw them on the grill. The recipe in the book has you peel the potatoes. I didn't, and the skin tasted good.... but not as good as the grilled insides.
Finish with salt and pepper (and sichuan pepper if you have it), and serve with a dipping sauce. (The book recommends a vinegar-soy sauce).