Peruvian Potato Mixed Grill

"Yet another recipe from Steven Raichlen's "The Barbecue Bible" for the ZWT Event. Here is his intro to the recipe: Where did the universally popular potato originate? There are numerous theories, but the evidence seems to point to Peru. This mountainous country in northern South America is the home of such distinctive potatoes as the purple potato and camote (a type of sweet potato, but not as sweet as ours). In fact, Peru probably grows more different types of potatoes than any other country in the world. The following recipe uses a variety of Peruvian potatoes, which are available at gourmet shops and specialty greengrocers. (The Yukon Gold isn’t strictly traditional, but it sure tastes good). The purple potato tastes similar to the North American boiling potato. The camote has a mild, nutty, semisweet flavor reminiscent of roasted chestnuts...."