Season chicken with ½ tsp salt and pepper to taste.
Coat skillet with cooking spray.
Over high heat, sear chicken until browned on both sides, about 2 minutes each.
Remove chicken from skillet and set aside.
Lower heat to medium.
Add onion and garlic to the skillet and sauté until they are soft, about 3 minutes.
Add rice to skillet with the veggies and toast the rice for a minute or two.
Add stock, remaining salt, and red pepper flakes to the skillet.
Bring to a boil, cover, and lower to a simmer or low heat. Cook for 8 minutes.
Remove cover and layer broccoli and chicken over the rice.
Cover again and continue to cook for another 7 minutes.
Remove skillet from heat.
Stir in ⅓ cup of cheese into the rice mixture.
Top with remaining ⅓ cup.
Cover skillet again for about 5 minutes, or until cheese melts.
