Ever since our prehistoric ancestors first put food to fire, cooks have contrived ingenious and not always conventional ways to harness the flames. In this show we explore three unexpected techniques for grilling. The first stands the vertical rotisserie used in Mexico and the Middle East on its head (or at least on its side) to make a Yucatan classic: crusty juicy tacos al pastor. The second involves a piece of equipment you don't usually find at a barbecue-a roofer's torch-here, used to brulee a spectacular pineapple dessert. The third involves a mystery ingredient that virtually no one on the planet has ever grilled. I give you the improbable grill. TACOS AL PASTOR; VOLCANO PINEAPPLE; MYSTERY BOX CHALLENGE - SUNFLOWER.