Preheat oven to 375 degrees F. Spray a 9x13-inch baking dish with cooking spray.
Toss chicken pieces with 1 tablespoon fajita seasoning until well coated.
Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add chicken and cook for 4 minutes, stirring occasionally, until golden-brown. Transfer to a plate.
Add remaining 1 tablespoon olive oil to the same skillet. Add sliced peppers and onions and cook for 5 minutes until softened.
Sprinkle vegetables with remaining fajita seasoning, garlic powder, and cumin. Stir well.
Spread uncooked rice evenly in the prepared baking dish. Pour in chicken broth and add the can of diced tomatoes with green chilies.
Layer the sauteed peppers and onions over the rice, then arrange chicken pieces on top. Season with salt and pepper.
Cover tightly with aluminum foil and bake for 35 to 40 minutes, until rice is tender.
Remove foil and sprinkle shredded cheese over the top. Bake uncovered for 5 to 10 minutes until cheese is melted and bubbly.
Let rest for 5 minutes before serving. Garnish with fresh cilantro and serve with sour cream, avocado, and lime wedges.