Simmer chicken breasts in water with lemon slices, celery hearts and bay leaf until tender. Save chicken stock and set aside for sauce.
2
Melt butter in a medium saucepan, stir in flour and continue to stir over medium heat until it is smooth and bubbly.
3
Add 2 cups of chicken stock (add bouillon or concentrated stock to richen if desired) and stir into flour mixture. Cook and stir over medium heat until boiling. Add heavy cream, continue to stir until thickened. Add sherry and stir in completely.
4
Cook broccoli according to package instructions just until tender. Place in the bottom of a shallow 2 quart casserole.Preheat oven to 350 degrees.
5
Cut cooked chicken breasts into large strips and place over broccoli. Pour cream sauce over top, allowing it to seep down into the broccoli layer. Sprinkle with parmesan cheese.
6
Bake in preheated oven for 30 minutes or until cheese is slightly browned.
