Make-Ahead Chicken Divan Casserole

Ingredients

• 1.5 cups grated Cheddar cheese
• 0.5 cups shredded Parmesan cheese , or more to taste
• 4 cups fresh broccoli florets
• 1 tablespoon salted butter
• 1 package sliced fresh mushrooms , 8 ounce
• 0.5 cups diced onion
• 3 cloves garlic , minced
• 1 can condensed cream of mushroom soup , 10.5 ounce
• 0.5 cups sour cream
• 0.5 cups milk
• 0.25 cups mayonnaise
• salt and ground black pepper to taste
• 2 cups cooked rice , or more to taste
• 5 cups shredded cooked chicken , or more to taste

Instructions

1. 1

   Preheat the oven to 350 degrees F (175 degrees C).

2. 2

   Combine Cheddar cheese and 1/2 cup Parmesan cheese in a small bowl and set aside.

3. 3

   Place a steamer insert into a saucepan and fill with water to just below the bottom of the steamer. Bring water to a boil. Add broccoli, cover, and steam until tender, 2 to 6 minutes.

4. 4

   Meanwhile, melt butter in a large skillet over medium heat. Add mushrooms, onion, and garlic; sauté until soft, 5 to 7 minutes.

5. 5

   Whisk together condensed soup, sour cream, milk, and mayonnaise in a large bowl until smooth. Add 1/2 cup Cheddar-Parmesan mixture and season with salt and pepper. Add sautéed vegetables and stir to combine sauce.

6. 6

   Spread 1/2 cup cheese-vegetable sauce onto the bottom of a 9x13-inch casserole dish. Add cooked rice as the bottom layer. Add steamed broccoli as the next layer, then top with a layer of cooked chicken. Cover with remaining cheese-vegetable sauce. Pat down evenly and smooth with a spatula.

7. 7

   Bake in the preheated oven for 30 minutes. Sprinkle with remaining Cheddar-Parmesan mixture, plus extra Parmesan if desired, and continue to bake until browned, about 15 minutes more.