For the Casserole Base:

4 tablespoons unsalted butter

1 large yellow onion, finely diced (about 1 cup)

4 teaspoons fresh garlic, minced

⅓ cup all-purpose flour

2 cups chicken broth

2 cups whole milk, at room temperature

For the Main Filling:

4 cups fresh broccoli florets

2 cups rotisserie chicken, finely shredded

2½ cups sharp cheddar cheese, freshly shredded

For the Seasonings:

1 teaspoon kosher salt

1 teaspoon freshly ground black pepper

½ teaspoon cayenne pepper (adjust to taste)

For the Biscuit Topping:

1 can refrigerated buttermilk biscuits (6 count) or homemade biscuits

For the Garlic Butter Finish:

4 tablespoons butter, melted

1 teaspoon kosher salt

2 teaspoons fresh garlic, minced

1 tablespoon fresh parsley, minced

Cook Mode Prevent your screen from going dark

Prepare the Casserole Base:
Preheat the oven to 375°F (190°C). In a large saucepan, melt butter over medium heat. Add diced onion and minced garlic, cooking for 4-5 minutes until soft and translucent. Stir in the flour and cook for another 1-2 minutes to form a roux.
Make the Sauce:
Gradually whisk in the chicken broth and milk, stirring to avoid lumps. Bring the mixture to a simmer and cook for 5-7 minutes until it thickens. Season with salt, pepper, and cayenne pepper. Remove from heat and set aside.
Prepare the Filling:
In a large mixing bowl, combine broccoli florets, shredded rotisserie chicken, and cheddar cheese. Pour the creamy sauce over and mix thoroughly.
Assemble the Casserole:
Transfer the broccoli mixture into a greased 9×13-inch casserole dish. Arrange the biscuits evenly on top.
Bake the Casserole:
Place the casserole in the oven and bake for 25-30 minutes, or until biscuits are golden brown and cooked through, with bubbling filling around the edges.
Prepare the Garlic Butter Finish:
While baking, mix melted butter, salt, garlic, and parsley in a small bowl.
Finish the Casserole:
Once the casserole is done, immediately brush the biscuits with the garlic butter mixture. Let it rest for 5 minutes before serving.

Vegetarian Option: Omit the chicken and add more vegetables like mushrooms, carrots, or cauliflower for a vegetarian casserole.

Cheese Variations: Swap cheddar for Gruyère, Monterey Jack, or any cheese of your choice.

Spice Level: Adjust the cayenne pepper for a milder or spicier casserole.