Creating Keto Garlic Mushroom Chicken Casserole is a breeze if you follow these simple steps:

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Sauté Vegetables: In a skillet, heat olive oil over medium heat. Add sliced mushrooms and minced garlic, sautéing until mushrooms are tender (about 5 minutes).
3. Combine Ingredients: In a large mixing bowl, combine the shredded chicken, sautéed mushrooms and garlic, heavy cream, ½ cup of cheddar cheese, thyme, onion powder, garlic powder, salt, and pepper. Mix well until all ingredients are evenly coated.
4. Transfer to Casserole Dish: Pour the mixture into a greased 9×13-inch casserole dish, spreading it evenly.
5. Top with Cheese: Sprinkle the remaining ½ cup of cheddar cheese over the top of the casserole.
6. Bake: Place the casserole in the preheated oven and bake for 25-30 minutes, or until the cheese is bubbly and golden brown.
7. Garnish and Serve: Remove from the oven and let it cool slightly. Garnish with fresh parsley before serving.

These steps will guide you in creating this incredible casserole with ease.