in a large pan, combine the water,onion,celery leaves,and salt. Add the chicken and boil. Reduce heat to low after it starts to boil. Cover and simmer for 10 minutes or until chicken is no longer pink. Remove chicken. Cool slightly and cut diagonally.
Steam Broccoli until slightly tender while chicken is cooking,and set aside.
In a small sauce pan mix soup, milk, and Hollandaise sauce. Stir until combined well. Bring to a boil on medium. Reduce to low heat, and simmer for a minute. Stir in Sherry if desired, Worcestershire sauce, and lemon jiuce. Stir in the sour cream, and set aside.
Heat oven to 400 degree's. spray a 13 x 9 inch pan with oil. Place the Broccoli on the bottom pan in a layer. Sprinkle the Broccoli with half of the Parmesan cheese.
Place the sliced chicken on top of Broccoli. Cover with the sauce., and sprinkle the rest of the Parmesan on top.
Bake for 20 minutes until bubbly,and top is browned. You may brown the top quicker under the broiler for a minute. Spoon portions on to plate and serve.