Cook broccoli in a pot of salted water until tender. Drain.
Place large stalks of broccoli in a 9x13 baking pan, crosswise - the heads towards the sides, the stems towards the center.
Preheat your oven to 180° C (350° F).
In a saucepan on medium heat, melt the butter, when hot, whisk in the flour until smooth.
Pour the broth in all at once and whisk until sauce is thickened.
Stir in the cream, sherry, salt, and dash of black pepper.
Pour 1⅔ cups sauce in over the broccoli.
Top with the sliced chicken.
To the remaining sauce, stir in ¼ cup Parmesan.
Pour the sauce over the chicken and top with additional Parmesan as desired.
Bake for 20 minutes or until hot.
serve with sides of your choice, enjoy.