In a large skillet, heat the olive oil over medium heat and sauté the thinly sliced onions for about 15-20 minutes until caramelized.
Season the chicken thighs with salt, pepper, garlic powder, and onion powder. Sear the thighs in the skillet for 3-4 minutes per side until golden brown.
In a large mixing bowl, combine the cooked rice, chicken broth, and caramelized onions (including the chicken). Add dried thyme and adjust seasoning with salt and pepper. Mix well.
Pour the mixture into a greased 9x13 inch baking dish and nestle the seared chicken thighs on top.
Cover the dish with aluminum foil and bake for 25 minutes.
Remove the foil and sprinkle the shredded Gruyère cheese over the chicken thighs. Bake for an additional 15-20 minutes until the cheese is melted and golden brown.
Let the dish sit for about 5 minutes before serving. Top with crispy fried onions for added crunch.
Notes
For a beautiful presentation, serve individual portions in shallow bowls, garnished with fresh sprigs of thyme.