“Knish on a Stick”

OK, here it is, a Planet Barbecue first: Mashed potatoes like you’ve never seen—or tasted—before, unless you live in the oil rich Caucasus nation of Azerbaijan. Flavored with caramelized onion (so far so good) and lamb fat (OK, maybe not so good, but bacon makes a great substitute), these potatoes are guaranteed to melt in your mouth, not to mention enhance your reputation for out-of-the-box grilling. So how do you grill mashed potatoes? (Aside from the obvious: carefully?) The secret is to