Ingredients:

  • 4 cups Cooked Chicken Breast or Thighs, shredded or diced
  • 1 lb Fresh Broccoli Florets (or frozen, thawed and drained)
  • 1 tablespoon Olive Oil
  • ½ teaspoon Kosher Salt
  • ¼ teaspoon Black Pepper
  • 4 tablespoons Unsalted Butter (for sauce)
  • 4 tablespoons All-Purpose Flour
  • 2 cups Whole Milk, warmed slightly
  • 1 cup Chicken Stock (low sodium)
  • ½ teaspoon Onion Powder
  • ¼ teaspoon Ground Nutmeg
  • 1 teaspoon Dijon Mustard
  • 2 tablespoons Dry Sherry or Fresh Lemon Juice
  • 1 cup Shredded Sharp Cheddar Cheese
  • ½ cup Shredded Gruyère or Swiss Cheese
  • Salt and White Pepper, to taste
  • ½ cup Panko Breadcrumbs
  • ¼ cup Grated Parmesan Cheese
  • 2 tablespoons Unsalted Butter, melted (for topping)

Instructions:

  1. Preheat oven to 375°F (190°C). Lightly grease the 9x13 inch casserole dish.
  2. Blanch the broccoli florets: Bring a pot of salted water to a boil. Blanch the broccoli for 2–3 minutes until vibrant green and tender-crisp. Immediately plunge into ice water to stop cooking, then drain thoroughly.
  3. In the casserole dish, combine the drained broccoli, shredded chicken, olive oil, salt, and pepper. Set aside.
  4. Make the Roux: In a medium saucepan, melt the 4 tablespoons of butter over medium heat. Whisk in the flour and cook for 1–2 minutes, stirring constantly, until the roux is smooth and smells faintly nutty.
  5. Add Liquids: Gradually whisk in the warm milk, one third at a time, ensuring the mixture is completely smooth before adding the next batch. Once all the milk is incorporated, slowly whisk in the chicken stock.
  6. Thicken and Season: Bring the sauce to a gentle simmer, whisking frequently. Cook for 5–7 minutes until the sauce coats the back of a spoon. Reduce heat to low.
  7. Finish the Sauce: Remove the pan from the heat. Stir in the Onion Powder, Nutmeg, Dijon Mustard, Dry Sherry/Lemon Juice, Cheddar, and Gruyère. Stir until the cheese is completely melted and the sauce is smooth. Season generously with salt and white pepper.
  8. Pour the cheesy béchamel sauce evenly over the chicken and broccoli mixture in the casserole dish. Gently stir the contents of the dish to ensure everything is coated in the sauce.
  9. Prepare Topping: In a small bowl, combine the Panko breadcrumbs, Parmesan cheese, and 2 tablespoons of melted butter. Toss until fully coated.
  10. Top and Bake: Sprinkle the breadcrumb mixture evenly over the casserole. Bake for 30–35 minutes, or until the sauce is bubbly around the edges and the topping is golden brown and crispy.
  11. Rest: Remove from oven and let stand for 5–10 minutes before serving. This allows the sauce to set up properly.