Season the steaks with 1 teaspoon salt and 1/2 teaspoon pepper.
Mix 1 1/2 cups flour with the garlic powder and paprika in a shallow dish, and whisk the buttermilk with the egg in another dish.
Coat each steak in flour, buttermilk and flour again, pressing the final coating firmly, then rest the steaks on a rack for 10 minutes.
Heat 1/2 inch of oil in a cast-iron skillet to 350°F and fry the steaks in 2 batches for 3 to 4 minutes per side until crisp and at least 145°F; rest them for 3 minutes.
Pour off the oil, leaving 1/4 cup and the browned bits, and whisk in the remaining 1/2 cup flour over medium heat for 1 minute.
Whisk in the milk gradually, simmer for 4 to 5 minutes until the gravy coats a spoon, and season it with the remaining salt and pepper before serving over the steaks.