(Amounts depend on how much leftover chicken you have and your taste.  We usually use roughly equal amounts cheese and chicken, and eyeball the salsa.)

Leftover cooked chicken, bone & skin removed, torn into bite-size pieces.
Grated cheddar cheese
Salsa (your favourite)
Flour tortillas
Oil for frying (or for greasing the cookie sheet, if you prefer to bake)

Extras:
Cubed fresh tomatoes
Sliced black olives

Condiments:
Sour cream
Guacamole
More salsa!

Spoon some of the mixture onto half a flour tortilla, fold over the other half and press to make a semicircle pocket. 

Fry tortilla pockets until golden on each side.  (If you're off frying, you can also bake them in the oven until the cheese is melty. You could probably also grill on the barbecue -- if you try it, let us know how it works out.)

Serve with condiments & enjoy!

(This recipe also works well with leftover steak, tofu or refried beans. The great thing about this recipe is you can make just a single quesadilla or truckload full of them.)