Preheat the oven to 375°F (190°C).
In a large skillet, heat olive oil over medium heat. Add chopped onion and cook until softened, about 3-4 minutes.
Add the chicken pieces to the skillet and cook until lightly browned on all sides, about 5 minutes.
In a large mixing bowl, combine uncooked rice, chicken broth, Knorr Chicken Flavor Bouillon Mix, garlic powder, black pepper, dried thyme, and paprika. Stir well to mix.
Add the cooked chicken and onions from the skillet into the rice mixture. Stir in frozen peas.
Pour the entire mixture into a greased 9×13-inch casserole dish and spread evenly.
Cover the casserole dish tightly with aluminum foil and bake in the preheated oven for 40 minutes.
Remove the foil and sprinkle shredded cheddar cheese evenly over the top of the casserole.
Return the casserole to the oven uncovered and bake for an additional 5 minutes, or until the cheese is melted and bubbly.
Remove from oven and let stand for 5 minutes before serving.