Season the chicken breasts with garlic powder, onion powder, smoked paprika, salt, and black pepper. Heat olive oil in a skillet over medium-high heat, add the chicken, and sear for 4-5 minutes on each side. Remove from skillet and set aside.

In a saucepan, bring chicken broth and a pinch of salt to a boil. Stir in the rice, reduce heat to low, and cover. Simmer for 15-18 minutes until tender. Fluff with a fork and keep warm.

In the same skillet, melt butter over medium heat. Whisk in flour, cooking for 1-2 minutes until bubbly. Gradually pour in milk and chicken broth, stirring until smooth and thickened, about 4-5 minutes.

Mix in garlic powder, thyme, and Parmesan cheese. Return the chicken to the skillet, spoon sauce over, cover, and simmer for 10 minutes until fully cooked.

Serve by placing rice on plates, topping with chicken and sauce, and garnish with parsley.