You can use regular size bell peppers or mini ones. Slice into strips is large, into rings if small ones. Slice a jalapeno into rings. Remove seeds if for a milder taste. Slice or dice onion.
Pan roast or grill peppers and onion.
Spray both sides of tortillas with spray oil and heat one side, place cheeses, peppers, more cheese and top off with another tortilla. When cheese melts on bottom, flip and brown other tortilla while cheese melts.