1. Preheat your oven to 350°F. Grease a baking dish with butter or cooking spray to prevent sticking.

2. Season the chicken pieces with salt, pepper, and paprika. In a skillet over medium heat, cook the chicken until browned and cooked through. Remove from heat and set aside.

3. In the same skillet, sauté the chopped onion and minced garlic until softened. Add the halved mushrooms and cook until they release their moisture and become tender. Stir in the heavy whipping cream, chicken broth, lemon juice, and nutmeg. Bring the mixture to a simmer and cook for 2-3 minutes, allowing the sauce to thicken slightly.

4. In the prepared baking dish, layer the cooked chicken pieces. Pour the sauce mixture over the chicken, ensuring it’s evenly distributed. Sprinkle the Parmesan cheese over the top.

5. Place the baking dish in the preheated oven and bake for 25-30 minutes, or until the casserole is bubbling and the top is golden brown.

6. Remove the Keto Creamy Chicken Casserole from the oven and let it rest for a few minutes. Garnish with chopped parsley before serving.