Parsley Poach fish (see Easy Poached Fish recipe). Flake into small pieces; set aside. In medium saucepan, over medium heat, melt butter. Stir in flour, mustard and cayenne pepper. Reduce heat; gradually add milk, stirring constantly. Add Worcestershire sauce; continue cooking over medium heat until thickened. Gradually stir about 1/2 cup of hot mixture into eggs; return to mixture in saucepan. Continue cooking for 1 minute more, stirring constantly. Add cheese; stir until melted. Stir in fish; heat through. Place toasted muffin halves on baking sheet. Top each with tomato slice. Broil 3 to 4 inches from source of heat for 1 minute. Remove to serving plates; top with sauce. Garnish with parsley. Serve immediately.