In a large bowl, combine the sliced bell peppers, sliced onions, cilantro, oregano, chili powder, salt, garlic powder, and ground cumin. Toss until coated.
Preheat a large cast iron skillet over medium high heat with the oil.When the skillet is hot, add in the seasoned veggies.Fry the veggies, stirring often, for about 5 minutes until veggies begin to soften.
Move the veggies to one side and add the chicken to the other half of the pan.Cook, stirring often but keeping the food separate, until the chicken is cooked through and no longer pink about 5 minutes.