First, prepare your chicken breasts. Make sure they’re fully thawed, and remove any excess fat. Place them into in lightly greased cast-iron skillet or casserole dish, and add approximately ½ cup of water, and minced garlic.
Place the casserole dish into the oven and preheat the oven to 350°F. Bake your chicken in the oven until it reaches an internal temperature of 165°F. Tip: for a shorter cooking time, cut your chicken into small pieces and it will cook much faster.
While your chicken is cooking, prepare your green peppers and onions. When your chicken comes to temp, remove it from the oven, and shred the chicken.
Crank up the oven temperature, and add your sliced peppers and onions. Bake until they become caramelized.
Add your fajita seasoning, and cream of chicken soup, stir to combine. Top with shredded cheese, and place back into the oven at 425°F. Bake until your cheese is melty and beginning to turn brown in some areas. (Or broil on low for 5-10 minutes, keeping a very close eye on it.)
Remove from the oven, add cilantro if desired, then serve and enjoy!