Preheat oven to 400 degrees. In a large bowl, combine the chicken, onions and peppers. Toss with the oil and then sprinkle on chili powder, cumin, kosher salt, garlic powder and black pepper, making sure all the chicken and veggies are coated with the spices.
Line a sheet pan with parchment paper or silpat mat. Use 2 baking sheets if desired- this will allow the veggies to spread out for more caramelization. Bake the chicken and veggies for 23-25 minutes, stirring halfway through (chicken should reach an internal temperature of 165 degrees).
While chicken is baking, place cauliflower rice in a large non-stick skillet preheated on medium heat. Warm through for 5-7 minutes, stirring occasionally to prevent sticking. Once the cauliflower rice is tender, stir in the cumin, chili powder and drained can of black beans. Cook for 1 minute to combine and then turn off the heat.
Place all the components and fun toppings on the table and have fun creating your own veggie-packed chicken fajita bowls!