3cupscooked white rice(which equals 1 cup of uncooked rice)
Preheat oven to 350F and start heating the water in a medium saucepan for the broccoli.
Add the broccoli to the medium saucepan with water. Cook for only 2-3 minutes. Drain and set aside.
Preheat large skillet at medium high heat. Add olive oil. Add chopped onions, garlic and mushrooms and cook them for 4-5 minutes until softened.
Next add heavy cream, chicken stock, 1 cup cheese, salt, garlic powder and black pepper to the skillet. Bring the mixture to a simmering point allowing the sauce to thicken a bit, just about 2 minutes.
Add cookedrice and broccoli to the skillet with the sauce and mix well.
Transfer the mixture from the skillet onto a baking casserole. Sprinkle with the remaining cheddar cheese on top. Bake for 20 minutes.
Adapted from Sunny Anderson's Cheesy Mushroom and Broccoli Casserole (Food Network)