Lay 1 tortilla down and sprinkle about 2/3 of your grated cheddar cheese on top.
In a bowl combine your sliced chicken and the bbq sauce, toss to coat.
Place the bbq sauced chicken on top of the cheese.
Sprinkle a handful of frizzled onions on top of the chicken.
Place the remaining cheese on top of the onions.
Place the other tortilla on top.
Place 1/2 of the butter in a skillet and turn the heat to medium. Spread the other 1/2 of the butter on top of the tortilla on top of the quesadilla (so when you flip the quesadilla it's buttered)
Once the butter is hot and bubbling place your non-buttered quesadilla side into the pan.
Turn the heat down to medium-low. Let it cook 2-3 minutes, check for browning.
Once browned nicely, flip the quesadilla.
Cook that side for 2-3 minutes.
Serve hot and enjoy!