Remove skin and bone from chicken, then cut each breast in half. Place 1 chicken piece between two pieces of plastic wrap and pound to about 3mm thickness. Repeat with remaining chicken. Top each piece with a slice of cheese and a slice of ham. Roll up and secure with a wooden pick. Coat with mix as directed on package. Cover. Chill thoroughly 20 minutes.
To bake place on ungreased baking sheet and bake at 400 degrees F or (210 degrees C) for 20 minutes or until chicken is tender. To make sauce - brown mushrooms in butter and stir. Dissolve chicken bouillon in water then add, with remaining ingredients to onions. Cook and stir until mixture thickens. The sauce may be thinned with a little water or dry white wine if necessary.
Serves 6.