1. Saute onions until golden. Add mushrooms and cook over high heat until limp.
2. Combine sauteed vegetables with remaining ingredients, mixing well.
3. Stuff one-third cup of filling into each chicken capon. Place seam-side down into roaster pan.
4. Sprinkle with parsley flakes and paprika.
5. Bake at 400 degrees Fahrenheit for one hour. Serve with duck sauce.