Prepare the Chicken: Season chicken breasts with garlic powder, onion powder, smoked paprika, salt, and black pepper.
Heat olive oil in a large skillet over medium-high heat. Sear chicken for 4-5 minutes on each side until golden brown. Remove and set aside.
Cook the Rice: Bring chicken broth and salt to a boil in a medium saucepan. Add rice, reduce heat to low, cover, and simmer for 15-18 minutes until tender and liquid is absorbed. Fluff with fork and set aside.
Make the Sauce: In the same skillet, melt butter over medium heat. Whisk in flour and cook for 1-2 minutes until lightly golden.
Gradually add milk and chicken broth, whisking constantly to make smooth sauce. Stir in garlic powder, thyme, cheddar, and Parmesan. Cook 3-4 minutes until thickened and cheese melted.
Combine Everything: Return chicken to skillet, spoon sauce over top. Cover and simmer on low for 10 minutes until chicken is cooked through.
Serve: Plate rice, top with smothered chicken and sauce. Garnish with fresh parsley and serve immediately.