Step 1

Slice the meat against the grain into thin strips, about ¼-inch thick (you could also cut it into small cubes); season with salt and pepper. Coat a large skillet with cooking spray and heat over medium-high heat. Sear the beef strips, doing your best not to overcrowd them, for a couple of minutes on each side or until cooked to your liking; transfer to a bowl.

Step 2

Add butter to the skillet. When melted, add garlic and mushrooms. Cook until the mushrooms brown and liquid evaporates, stirring occasionally. Add cooked mushrooms to steak and toss to combine.

Step 3

Wipe the skillet clean with paper towels (alternatively, you can use a griddle or a grill). Reduce heat to medium.

Step 4

Sprinkle about 2 teaspoons of cheese evenly over half of each tortilla. Divide the mixture evenly among tortillas (also to cover just one side) and sprinkle with remaining cheese. Fold tortillas in half over the filling.

Step 5

Carefully coat both sides of quesadillas with cooking spray. Cook quesadillas 1-2 minutes on each side or until browned and cheese melts (use a spatula to hold the quesadilla in place, and flip it over). Repeat with remaining quesadillas.

Step 6

Serve with salsa or your favorite sauce.