In a saucepan, melt 3 tbsp butter. Stir in flour until smooth. Gradually stir in broth and milk. Bring to a boil; boil and stir for 2 minutes. Remove from heat.
In skillet, sauté onion in remaining butter until tender. Add the crab, mushrooms, cracker crumbs, parsley, salt, pepper and 2 tbsp of white sauce; heat through.
Flatten chicken breast halves to 1/4" thickness. Spoon about 1/2 cup of the crab mixture onto each chicken breast half. Roll up and secure with a wooden toothpick. Wrap 1 slice of bacon around each breast half. (optional) Place in either a greased baking dish or in a zip top freezer bag. Add the remaining white sauce. Wrap, label and freeze.
To prepare: Thaw chicken breast halves in refrigerator.
Bake, covered at 350 degrees for 30 minutes or until chicken juices run clear.
Sprinkle with Swiss Cheese and paprika. Bake, uncovered, 5 minutes longer or until cheese is melted.