Preheat your oven to 375°F and lightly grease a 9x13-inch baking dish with non-stick cooking spray.
Heat the olive oil in a large skillet over medium-high heat. Add the ground turkey and chopped onion, cooking for 5-7 minutes while breaking the meat apart with a spoon until it is no longer pink and the onion is soft.
Stir in the minced garlic and cook for 1 more minute until fragrant, then drain any excess liquid from the skillet.
In a large mixing bowl, combine the chicken broth, uncooked rice, sour cream, cream of mushroom soup, dried parsley, garlic powder, black pepper, and salt. Whisk until the mixture is smooth and fully combined.
Fold the cooked turkey mixture, 1 cup of the shredded cheddar cheese, and the thawed peas into the rice mixture until everything is evenly distributed.
Pour the entire mixture into the prepared baking dish and spread it into a smooth, even layer. Cover the dish tightly with aluminum foil.
Bake for 45 minutes, then remove the foil. The rice should be tender and have absorbed most of the liquid. Sprinkle the remaining 1 cup of cheese evenly over the top.
Return the casserole to the oven, uncovered, and bake for another 10-15 minutes until the cheese is completely melted and bubbly. Let it stand for 5 minutes before serving to allow it to set.
