Preheat oven to 350 degrees (when you’re ready to bake).
Thaw chicken breasts and slice width wise to get 4 thin chicken breast pieces.
Slice green peppers and onions and place in plastic bags. Right before placing on sheet pan, drizzle in about 1 tsp of olive oil to each bag as well as 1/2 Tbsp grill seasoning to each. Shake around until veggies are evenly coated.
When ready to bake, line a sheet pan with aluminum foil, and drizzle with a small amount of olive oil.
Lay chicken breasts onto sheet pan and sprinkle with 1 Tbsp of the grill seasoning.
Evenly distribute the seasoned veggies around the chicken on the sheet pan.
Bake for 15 minutes or until chicken is cooked through. Remove chicken from the pan, slice into bite size pieces and return it to the pan.
At this point, I like to move everything into the middle of the pan. Lay the cheese slices over the veggies and chicken so that everything is covered by the cheese.
Switch oven to broil (I set mine to 550 degrees), and place pan back in oven for 5 minutes. Remove and serve on buns, hoagies, or whatever bread you choose loaded with mayo (or chipotle aioli is great with these)!