In a large mixing bowl, combine the diced chicken and broccoli florets.
In a separate mixing bowl, whisk together the chicken broth, heavy cream, mayonnaise, shredded cheddar cheese, grated Parmesan cheese, chopped onion, minced garlic, paprika, salt and pepper to taste.
Pour the mixture over the chicken and broccoli and stir until everything is evenly coated.
Transfer the mixture to a greased 9×13 inch casserole dish.
Bake the casserole in the preheated oven for 25-30 minutes, or until the top is golden brown and the casserole is heated through.
Remove the casserole from the oven and let it cool for a few minutes before serving.
Enjoy your delicious Keto Cream of Chicken Broccoli Casserole!