You’ll find quesadillas of all types in Mexico. In Mexico City, they’re often made from fresh masa and without cheese; in other parts of the country, they’re made with flour tortillas, with lots of melty Oaxaca cheese. Fillings vary from stewed or griddled meat to squash blossoms to nopales (cactus paddles). In this recipe, we stuff tortillas with a mixture of sautéed mushrooms and cheese, with a little smoky and spicy heat from a chipotle chili. Made with 4- to 5-inch flour tortillas, the quesadillas are perfect for a lunch or snack. If you can’t find queso Oaxaca, any mild melting cheese, such as mozzarella or muenster, will work. Lard is traditional for cooking these quesadillas, but for a vegetarian version, use grapeseed or another neutral oil. For best browning, cook these in a nonstick skillet.