Preheat oven to 350°

On your stovetop in a sauté pan, add the butter and the onion. Cook the onion until it is translucent, but not brown.

Add the frozen broccoli and cook until fully defrosted.

Add the soup and combine.

Add the rice and 3/4 of the grated cheese, and combine everything.

Spoon into oven safe dish and sprinkle remaining cheese over the top.

Bake for 30-45 minutes, or until heated all the way through.