In Mexico, quesadillas are made on a comal, a flat, round griddle-like pan that’s also used for cooking tortillas and toasting chilies. The closest piece of cookware in most U.S. home kitchens is a 12-inch skillet, which is what we use here. Along with the cheese, earthy poblano chilies and charred sweet corn are the star ingredients, but we add ground cumin for savoriness and spice, plus pickled jalapeños and a little of their brine for some chili heat and acidity. In summer months, plump, tender kernels cut from just-shucked ears of corn are best, but frozen works, too; be sure to fully thaw the kernels and pat them dry so they brown well when toasted. Queso Oaxaca is a mild, stringy melting cheese and the first choice for making quesadillas. If you cannot find it, pepper jack is a great, though slightly less gooey, option that also offers a little kick of heat, or you could simply use whole-milk mozzarella.