Saute onions and mushrooms in 2 tablespoons of oil until limp.
Drain, combine with broccoli and set aside.
Combine cheese, eggs, mayonnaise, water and rice.
Brown chicken breasts in 3 tablespoons of oil.
To Assemble: Combine broccoli mixture with cheese mixture and pour into greased, shallow baking pan.
Place chicken breasts on top and sprinkle with paprika.
Bake uncovered in a 350 oven for 45 minutes.
NOTE- You may cut fat and cholesterol from this recipe with the following substitutions: light skim milk cheese for cheddar, 4 ounces of egg substitute for the 2 eggs, light mayonnaise for regular mayonnaise and non-fat cooking spray for browning chicken.