Put chicken in a large baking dish and sprinkle on the pepper, salt, and garlic powder. Refrigerate chicken for 1 hour.
Put the flour in a large, sturdy plastic bag. Add the chicken, a few pieces at a time, and shake to coat. Remove from the bag and shake off any excess flour.
In a large cast iron skillet, heat the oil until shimmering. Carefully drop chicken into the uncovered skillet and fry over moderate heat, turning until golden brown and cooked through, about 30 minutes. Lower the heat if the chicken gets too dark. Remove and drain excess oil on paper towels.