Mix the first 7 ingredients together to make the fajita seasoning together.
Brush the chicken with half of the olive oil and sprinkle evenly with the fajita seasoning, reserving some seasoning for the peppers and onions.
Grill the chicken until it reaches an internal temperature of 165º. Let set for 10 minutes and slice.
While the chicken is on the grill, sauté the peppers and onions on high heat in the remaining oil and seasoning mix in a pan on the stovetop. Cook until they are crisp and tender.
To assemble meals to eat later, evenly distribute the pepper mixture into prep containers and top each evenly with equal amounts of the chicken breast slices. Top each evenly with the cheese and sprinkle with sliced green onions. Cover and refrigerate until you are ready to enjoy. You can add cooked rice to each meal if you like.