Season the chicken breasts with garlic powder, onion powder, smoked paprika, salt, and black pepper. Heat olive oil in a large skillet over medium heat. Cook chicken 5-7 minutes per side until golden and cooked through (165°F internal temperature). Set aside.
In a medium saucepan, combine rice, 2 cups chicken broth, and 1/2 tsp salt. Bring to a boil, then cover and reduce heat to low. Simmer for 15-18 minutes until rice is cooked and liquid is absorbed. Fluff with a fork and set aside.
In the same skillet used for chicken, melt butter over medium heat. Whisk in flour for 1-2 minutes to form a roux. Slowly add milk and 1/2 cup chicken broth, whisking to avoid lumps. Simmer until thickened, about 3-5 minutes.
Add garlic powder, thyme, salt, and pepper to the sauce. Stir in cheddar and Parmesan cheeses until smooth and creamy.
Stir cooked rice into the creamy sauce. Plate rice, top with chicken, spoon extra sauce over, and garnish with parsley.
Notes
Try quinoa instead of rice for a protein boost or swap chicken for mushrooms for a vegetarian version. Customize with your favorite spices!