We challenged chefs of three different skill levels - amateur Stephen, home cook Lorenzo, and professional chef Frank from the Institute of Culinary Education - to whip us up some nachos. After each of them had presented their creation, we asked food scientist Rose to weigh-in on their choices. Which crunchy, cheesey, melty, spicy....? Yikes, sorry. Got a little distracted. These look amazing. I want nachos.