Creating French Onion Chicken Orzo Casserole is easy when you follow these straightforward steps:

1. Preheat the oven to 375°F (190°C).

2. Cook the Onions: In a large skillet, heat olive oil and butter over medium heat. Add sliced onions and cook for 15-20 minutes until caramelized, stirring frequently. Add minced garlic and cook for an additional 1-2 minutes.

3. Cook Chicken: In the same skillet, add diced chicken to the onions. Cook for about 5-7 minutes, until the chicken is no longer pink.

4. Add Orzo: Stir in orzo pasta, thyme, salt, and pepper. Mix well to combine the ingredients.

5. Combine Liquids: Pour in the chicken broth and heavy cream. Bring to a simmer and cook for 5 minutes, stirring frequently. The orzo should start to soften, but it doesn’t need to be fully cooked at this stage.

6. Transfer to Casserole Dish: Pour everything into a greased casserole dish and spread it out evenly.

7. Add Cheese: Sprinkle the shredded Gruyère and mozzarella cheese evenly on top of the casserole.

8. Bake: Cover the casserole with aluminum foil and bake for 25 minutes. Then, remove the foil and bake for an additional 15 minutes, or until the cheese is bubbly and golden.

9. Garnish: Once out of the oven, let it cool for about 5 minutes. Garnish with chopped fresh parsley before serving.

10. Serve: Scoop out portions and serve warm. Enjoy the aromatic and flavorful experience of this delicious casserole!