1 (10 oz.) pkg. frozen chopped broccoli cooked and drained
3 c. rotelli or corkscrew pasta, cooked (approximately 6 oz. dry pasta)
In a small saucepan, combine onion and water. Cook covered over medium heat 5 minutes. Do not drain. In a small saucepan, combine milk, cornstarch, and pepper; add to onion. Cook and stir constantly until thick and bubbly. Cook, stirring constantly 1 minute more. Add cheese, stir to melt. Add mushrooms. Cover and set aside.
In a large bowl, combine chicken, broccoli, pasta, and half of the mushroom cheese sauce. Mix well. Spoon into a medium casserole dish coated with non stick vegetable spray. Top with remaining mushroom cheese sauce. Bake at 350 degrees for 20 minutes. Makes 6 servings, 1 cup each.