Cartagena Beef Kebabs

There’s one in every city in Latin America—a street corner grill jockey whose kebabs fill the skewer a little more generously, whose grill sizzles a little louder, and whose stall or pushcart is busier than everyone else’s. In the colonial city of Cartagena, this go-to guy is Piedro “Peter” Goncales. For more than a quarter century, Goncales has dished up amazingly cheap and spectacularly flavorful beef kebabs, using a square of cardboard to fan the embers hot enough to apply the right char