Steak Quesadillas

These quesadillas are all about the embrace of melty mozzarella and warm, delicate flour tortillas, filled with succulent bites of salt-and-pepper steak. Instead of two tortillas united by cheese, this style of quesadilla uses only one, stuffed then folded. Cheese still defines and binds the dish, but it isn't the only central character. Smashed avocado adds a lighter, fresher kind of richness, and a sprinkling of cilantro and onion lend a bright, zippy crunch. Inspired by the quesadillas served at Taquería Frontera in Los Angeles, where cheese plays a lighter role, this balanced recipe uses a skillet-melt technique in which a slice of cheese is melted directly in a pan, then a tortilla is laid on top so that the two adhere. All you need is a sturdy metal spatula to shimmy underneath them both, flip and reveal a cheesy filling that can range from just melted to lightly crisp.