Preheat an oven to 375˚F. Spray a 9”X 9” baking dish with nonstick cooking spray and set aside. 

While the oven is heating, brush the chicken breasts with a little olive oil to coat. Sprinkle with salt and pepper and place on a sheet pan.   Place the broccoli florets in a bowl and toss with 2 tablespoons of olive oil and ½ tsp. of salt. When they’re well coated with the oil, spread the broccoli florets out onto a separate sheet pan. Place both sheet pans in the oven. Bake the broccoli florets for 15-20 minutes, or until they’re just cooked through, and bake the chicken for 20-25 minutes, or until it’s cooked through and the juices run clear.  Allow the chicken to cool for 5 minutes before cutting into ½-inch chunks. You should have about 2 cups of diced chicken.

If baking immediately, leave the oven at 375˚F.

While the chicken and broccoli are roasting, make the sauce. In a medium saucepan, melt the butter over medium heat. Once it’s melted, whisk in the flour, and cook for 1 minute, whisking constantly. Add the chicken broth and keep whisking until it starts to thicken, breaking up any lumps as you stir. Reduce the heat to low and whisk for 3 more minutes. Whisk in the cream (or half-and-half), stirring for 1 more minute, then remove it from the heat. Stir in the sherry, parmesan cheese, ¾ cup of the cheddar cheese, and ¼ tsp. salt and ¼ tsp. pepper. 

Add the cooled chicken and broccoli to the sauce and stir to combine.  Pour the entire mixture into the prepared baking pan. Sprinkle the remaining ¾ cup of cheddar cheese on top. Sprinkle the almonds over the cheese and cover with aluminum foil. (You can refrigerate it at this point for the day.)