Chicken Divan was first invented at the Divan Parisienne Restaurant in the New York City Chatham hotel. A mixture of chicken, broccoli, almonds, and a cheese sauce, the dish is a classic casserole. The recipe below calls for both Parmesan and cheddar cheese for a super-rich cheese sauce.
The only slightly technical part of this recipe is making the béchamel sauce, which is the base of the cheese sauce. To do this, you'll need to whisk the butter and flour together until smooth, then slowly add the milk until you get a nice, thick sauce into which you can melt the cheese.
Heat the butter in a heavy-bottomed pot over medium heat. Sprinkle in the flour, and whisk together. Cook for 1 minute, then begin drizzling in the milk, whisking constantly. When all of the milk is added, add the chicken stock. Continue to cook until the mixture is thick and bubbly, then remove from the heat.
Add the nutmeg, half the Parmesan, and half the cheddar to the sauce and whisk until smooth.
Toss the chicken, broccoli, and sauce together and pour into a baking dish. Sprinkle the remaining cheese over the top.
Cover the casserole and bake for 15 minutes, then remove the foil and bake for an additional 15 minutes, until bubbly.