Brine chicken breasts for 2-6 hours using this brine recipe, or whichever brine you prefer. This is key, don't skip this step!
Bake chicken at 450 for about 20-30 minutes until done.
Cook rice as per package instructions.
Steam broccoli for about 5 minutes.
In a medium to large frying pan or dutch oven, heat olive oil and saute onions for about 5 minutes.
Add the milk and cream of mushroom. Heat through.
Dice the cooked chicken and add to the frying pan along with the rice and broccoli.
Add salt and pepper to taste. Stir to combine.
Spray a casserole dish with oil and transfer to the casserole dish. If using a dutch oven, leave it in the dutch oven.
Sprinkle cheese on top.
Cover and bake in a 400 degree oven for about 10-15 minutes until the cheese melts.