In a large skillet, heat 2 tablespoons of butter and 1 tablespoon of olive oil over medium-low heat. Add sliced yellow onions and cook for 30-40 minutes until golden brown, adding minced garlic for the last minute.

Season 1 pound of boneless chicken thighs with salt and pepper. In a separate skillet, heat olive oil and brown the chicken for 5-7 minutes until golden, not fully cooked.

Combine caramelized onions with 1 cup of beef broth, 1 cup of orzo pasta, 1 cup of heavy cream, and 1 teaspoon of fresh thyme. Add browned chicken and simmer for 5-7 minutes.

Preheat oven to 375°F (190°C). Mix half of the Gruyère cheese into the orzo mixture, transfer to a greased baking dish, top with remaining cheese, and bake for 20-25 minutes.

Let cool for 5-10 minutes before serving. Garnish with fresh thyme or parsley.