Chicken and Broccoli Casserole

4 skinless, boneless chicken breast halves
1 small onion, quartered
1 tablespoon margarine
2 cups sliced fresh mushrooms
1 (10 oz.) package frozen chopped broccoli
1/4 teaspoon ground nutmeg
1/4 teaspoon salt
Freshly ground pepper to taste
4 teaspoons grated Parmesan cheese


Directions:
Cook the broccoli according to package directions. Drain and set aside. Meanwhile, begin cooking the chicken. In a medium-sized saucepan, cover chicken breasts and onion quarters with water. Place the lid on the pan and poach the chicken over medium-low heat until meat is white all the way through, about 20 minutes. While the chicken is cooking, melt the margarine in a large skillet. Add mushrooms and cook until tender, about 5 minutes.  Preheat the broiler. Place cooked broccoli in an 8-inch square baking dish. Sprinkle with nutmeg, salt and pepper. Drain the cooked chicken and onion; arrange  in a single layer over broccoli. Top with mushrooms. Sprinkle with cheese. Broil 1 to 2 minutes or until cheese is melted. Serve hot.

Notes:
From Rebecca Goss, my friend and a fellow AAFES wife in Berlin, Germany, in the early 1990s.