Crispy, cheese-oozing pieces of heaven — these grilled quesadillas pair perfectly with a cold margarita on a hot summer night. If you don't have fresh buffalo to grill, substitute strips of chicken breast or flank steak. Once again, avocado provides a game-changing twist on this traditional mexican treat.
Heat a grill to high heat or very hot charcoals (you should be able to hold your hand over it for only 1-2 seconds). Rub the steak with the olive oil, and then with the garlic, scallions, mustard, soy sauce, salt, and pepper. Let sit until the grill heats up.
Place on the grill for about 5 minutes on each side or until a meat thermometer reaches 130 degrees internally for medium rare. (You can eat the steak as is or continue to cook make the quesadillas, if you are going to make them, then you will want to undercook the steak slightly.)
Remove the steak from the grill and allow to rest for 10-15 minutes, then slice into strips across the grain. Light oil the outside of the tortillas and place half of them on the grill over indirect heat and cook until crisp. Meanwhile, place the cheese, sliced avocado, and the buffalo slices on the other tortilla halves. Place on the grill over indirect heat and close with a crisp tortilla half. Press down on the tortillas a couple of times while on the grill until the cheese is melted and the other tortilla is crispy. Serve immediately with salsa and sour cream if desired.