Heat olive oil in a large skillet over medium heat. Add the sliced onions and cook for 10-15 minutes until they’re caramelized and golden brown, stirring periodically.

In a separate pot, boil water and cook the orzo according to package instructions (usually about 8-10 minutes). Drain and set aside.

In a large mixing bowl, combine the cooked orzo, shredded chicken, caramelized onions, chicken broth, heavy cream, garlic powder, thyme, salt, and pepper. Stir until everything is well mixed.

Pour the mixture into a greased baking dish, spreading it out evenly.

Sprinkle the Gruyère cheese and panko breadcrumbs evenly over the top.

Preheat your oven to 375°F (190°C). Bake for 25-30 minutes, or until the top is golden brown and bubbly.

Let the casserole sit for 5-10 minutes after removing it from the oven before serving.