1. Preheat oven to 350 degrees.
2. Coat the small casserole with cooking spray.
3. Heat skillet to medium, and add broccoli, onion, and water. Cook for 8 minutes.
4. Meanwhile, combine milk, eggs, 3/4 of the cheese, and pepper in large bowl. Set aside.
5. When broccoli mixture is finished cooking, add it to the egg mixture and stir briefly.
6. Fill the bottom of the bigger casserole dish with about 1 inch of water.
7. Place the egg/broccoli mixture into the smaller casserole dish.
8. Put the smaller dish into the bigger dish.
9. Bake at 350 degrees for 45 minutes, uncovered.
10. Remove from oven, remove small casserole dish from big one.
11. Sprinkle remaining cheese over the casserole and serve.