Melt butter in saucepan. Add flour and stir until smooth and bubbly. Stir in stock and cream. Cook and stir over low heat until thick and smooth and ready to boil. Season with walt, pepper, celery salt, and onion juice. Beat egg yolks with water, lemon juice, and sherry. Add with chicken and pimiento to cream and cook slowly for a minute or two. Garnish with rings of green pepper and olives cut from pits. Serve with hot crisp toast or over rice or in patty shells.