To start off, preheat your oven to 375°F (190.6°C).
Then take your cast-iron skillet and place it over medium heat on your stovetop. Add butter and garlic. Allow the butter to melt. As your butter is nothing, add your chicken breast into the skillet, and sprinkle with your garlic, salt, salt, pepper, and onion powder. Make sure to season on both sides of your chicken breast.
Increase your burner temperature to medium-high. Sere your chicken breast on each side, then removed it from the heat. Pour the chicken broth into your cast-iron skillet, this will help to keep the chicken moist as it bakes.
Cover your cast-iron skillet with an oven-safe lid, and place it into the oven for 45 minutes to 1 hour or until the internal temperature of your chicken reaches 165°F on an instant-read thermometer.
When your chicken reaches an internal temperature of at least 165°F, it may be removed from the oven, allow to rest for a few minutes, then serve and enjoy.