It's amazingly simple and goes against what many cooks outside of Mexico learn: instead of coating vegetables with oil and sticking them in a hot oven, Mexican cooks roast them without oil until they're nicely browned. This technique is essential to re-creating the flavors of my country, the slight bitterness imparted by the char and the intensity of the flavors it creates. —Roberto Santibañez, Fonda, New York City