Drain salmon, reserving 1/2 cup liquid. Set liquid aside. Flake salmon. Melt butter in pan over low heat. Add flour, stirring constantly. Gradually add reserved liquid and milk. Cook over medium heat, stirring constantly until thick. Remove from heat. Add onion, parsley, dry mustard, lemon juice, salt, pepper, Beau Monde seasoning, and hot sauce, stirring well after each addition. Stir in salmon, egg, and 1/2 cup breadcrumbs. Shape into 6 patties. Dredge in 1/2 cup bread crumbs. Fry in hot oil for 5 minutes on each side. Drain. Serve with Lemon Cheese Sauce: Mix butter and flour and cook for 1 minute. Stir in milk and cook until thick. Add seasonings and stir. Add 1/4 cup of hot mixture to egg yolk. Add to remaining mixture. Add cheese and lemon juice and stir for 2 minutes. Pour over salmon. Formatted by Mary Dishongh Bowles.