Wipe chicken breasts with damp cloth. In large skillet, bring broth to boiling. Add chicken; reduce heat; simmer covered, 20 minutes or until tender. Remove chicken; reserve broth.
In medium skillet, melt butter; saute onion and mushrooms 2 minutes. Remove from heat; stir in flour and nutmeg. Gradually stir in milk and 1 1/2 cups reserved broth. Bring to boil; simmer 1 minute. Remove from heat.
Preheat oven to 400 degrees. Remove skin from chicken breasts. Arrange chicken in a shallow baking dish. Pour mushroom sauce over all.
Arrange ham slices between chicken breasts. Sprinkle Parmesan over top. Bake, uncovered, 15 minutes or until cheese is browned. 6 servings.
