Place unopened packages of Broccoli on end in microwave oven.
Microwave on high for 4-5 minutes, turning over after 2 minutes, then set aside.
In 3 quart casserole or 9x13 glass baking dish, combine Rice, Soup, Milk, Cheese, Salt, and Pepper.
Microwave on high for 2-4 minutes.
To cheese mixture, add Celery, Water Chestnuts, Broccoli and Chicken; stir thoroughly.
Microwave on high for 25 minutes.
Let stand 5 minutes before serving.