1. 1. Prep Ingredients: Dice chicken into 1-inch pieces. Finely dice onion. If using fresh cauliflower, rice using a food processor or box grater. If using frozen, thaw completely and squeeze out excess moisture using a clean kitchen towel. Preheat oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish.

2. 2. Cook Chicken: Heat olive oil in a large oven-safe skillet or Dutch oven over medium-high heat. Add diced chicken, season with salt and pepper, and cook 5-7 minutes until browned and cooked through. Remove chicken and set aside.

3. 3. Sauté Aromatics and Cauliflower: In the same skillet, add diced onion and cook 3-5 minutes until softened. Add riced cauliflower and cook 5-7 minutes, stirring occasionally, until slightly softened.

4. 4. Create Creamy Sauce: Reduce heat to medium-low. Add softened cream cheese and stir until melted and smooth. Pour in chicken broth and milk, stirring continuously until creamy. Add sour cream (or Greek yogurt), garlic powder, onion powder, Italian seasoning, and 1/2 cup cheddar cheese. Stir until cheese is melted and sauce thickens slightly. Season generously with salt and pepper.

5. 5. Combine: Return cooked chicken to the skillet and stir to coat evenly with the sauce.

6. 6. Assemble: Transfer mixture to the prepared baking dish and spread evenly. Top with remaining 1/2 cup cheddar cheese and 1/2 cup mozzarella cheese.

7. 7. Bake: Bake for 20-25 minutes until bubbly and cheese is melted and lightly golden. For a deeper golden crust, broil for 1-2 minutes, watching closely.

8. 8. Rest and Serve: Remove from oven and let rest 5-10 minutes before serving. Garnish with fresh parsley or chives if desired.