Preheat oven to 400°F.
Spritz a medium skillet with cooking spray and add onions. Saute until translucent.
While the onions are sauteing, mix together dry spices.
Place chicken strips in a large bowl, add the spice mixture and toss to coat.
To the coated chicken, add the sauteed onions, tomatoes, peppers and green beans (optional). Stir to combine.
Spritz a 9x13 baking dish with cooking spray. Pour in the chicken fajita mixture and bake uncovered for 35-40 minutes or until chicken is cooked through and vegetables are tender.
In the last five minutes of baking, steam the cauliflower rice in a pot on the stove or in the microwave.
Serve chicken fajitas over Cauliflower Rice.