Creating the French Onion Chicken Orzo Casserole can be simple if you follow these straightforward steps:

1. Preheat the Oven: Set your oven to 350°F (175°C) to prepare for baking.

2. Sauté Onions: In a large skillet, heat butter and olive oil over medium heat. Add the sliced onions and cook until caramelized, about 15-20 minutes. Stir occasionally to avoid burning.

3. Prepare Chicken: Season the diced chicken with garlic powder, onion powder, thyme, salt, and pepper. Add to the skillet with the onions, cooking until the chicken is browned.

4. Cook Orzo: Stir in the orzo pasta and beef broth into the skillet. Bring to a simmer, then reduce heat to low. Cover and let it simmer for around 10 minutes, or until the orzo absorbs the liquid and is tender.

5. Combine Ingredients: Once cooked, remove from heat. Stir in half of the Gruyère and mozzarella cheese into the mixture, allowing it to melt.

6. Transfer to a Baking Dish: Pour the orzo and chicken mixture into a greased casserole dish, spreading it out evenly.

7. Add Cheese Topping: Sprinkle the remaining Gruyère and mozzarella cheese over the top of the casserole.

8. Bake: Place the casserole in the oven and bake for 20-25 minutes, or until the cheese is bubbly and golden brown.

9. Rest: Once it’s out of the oven, let the casserole rest for 10 minutes to allow it to set before serving.

10. Garnish: Top with freshly chopped parsley for added color and flavor.

These steps will guide you through making this incredible casserole, ensuring a delightful dining experience for you and your loved ones.