Preheat oven to 375 degrees F. Lightly grease a 9x13 inch baking dish.
Add the thinly sliced onion, white rice, beef broth, chicken broth, and packet of French onion soup to the baking dish.
Top with the chicken thighs, making sure to nestle them into the liquid and rice.
In a small bowl combine the garlic powder, onion powder, paprika, salt, and black pepper. Whisk together and then sprinkle over the chicken thighs.
Cut the butter into 8 equal slices and place them evenly over the chicken.
Cover the dish tightly with foil and place in the oven to bake for 1 hour.
After 1 hour, take the dish out of the oven and remove the foil. Sprinkle the shredded Gruyere or Swiss cheese over the dish and top with the crispy onion topping.
Place the dish back in the oven and bake for 10 minutes or until the cheese is melted.