Bring a large skillet sprayed with nonstick spray to medium-high heat. Add chicken, and season with 1/8 tsp. each salt and black pepper.
Add veggies, 1/2 tsp. garlic powder, 1/2 tsp. onion powder, and 1/4 tsp. oregano. Cook and stir until chicken is cooked through and veggies are soft, 8 - 10 minutes.