I have never written this down so all of the amounts are estimates of what I use.

chicken breasts, cut into bite size pieces
mozzarella cheese, shredded
1 medium onion, cut into slices
mushrooms, enough of liking

Cook chicken in frying pan with just a bit of olive oil. (Or you can grill the chicken) Stirfry the onions and mushrooms together. Once chicken is finished combine both and melt the cheese on top.

I usually served this with grilled asparagus or mashed potatoes.