Creating French Onion Chicken Orzo Casserole is quite simple. Here’s how you can make it:

1. Preheat the Oven: Preheat your oven to 375°F (190°C).
2. Cook Onions: In a large skillet, heat olive oil over medium heat. Add the sliced onions and cook until they are caramelized and golden brown, about 15 minutes. Stir occasionally.
3. Add Garlic: Add minced garlic to the skillet and sauté for an additional 1-2 minutes, until fragrant.
4. Cook Chicken: In the same skillet, add the diced chicken. Cook until it is no longer pink, about 5-7 minutes.
5. Season Mixture: Stir in the thyme, salt, and pepper to taste. Mix well to combine.
6. Combine Ingredients: In a large bowl, combine the cooked orzo, chicken mixture, chicken broth, and heavy cream. Stir until well mixed.
7. Layer in Casserole: Pour the mixture into a greased 9×13 inch baking dish. Sprinkle the Gruyère cheese evenly over the top.
8. Bake: Cover with foil and bake in the preheated oven for 20-25 minutes. Remove the foil and bake for an additional 10-15 minutes, until the cheese is bubbly and golden brown.
9. Garnish: Once baked, remove from the oven and let cool slightly. Sprinkle with fresh parsley before serving.

Follow these steps to create a beautifully layered dish that encapsulates the flavors of French onion soup and the hearty feel of a casserole.