Combine the paprika, black pepper, garlic powder, oregano, and cayenne in a small bowl and mix thoroughly with a fork. In a separate bowl, whisk the buttermilk, egg, 1 tablespoon salt, and 2 tablespoons of the spice mixture. In another bowl, whisk together the flour, cornstarch, baking powder, 2 teaspoons salt, and the remaining spice mixture.
Coat steaks in dry mixture, then wet, then dry again.
Adjust an oven rack to the middle position and preheat the oven to 350°F. Heat the shortening or oil to 425°F in a 12-inch straight-sided cast-iron pan over medium-high heat. Adjust the heat as necessary to maintain the temperature, being careful not to let the fat get any hotter.
One piece at a time, transfer the coated steak to a fine-mesh strainer and shake to remove excess flour. Transfer to a wire rack set on a rimmed baking sheet. Once all the chicken pieces are coated, place in the pan. The temperature should drop to 300°F; adjust the heat to maintain the temperature at 300°F for the duration of the cooking. Fry until it’s a deep golden brown on the first side, about 6 minutes; do not move it or start checking for doneness until it has fried for at least 3 minutes, or you may knock off the coating. Carefully flip the steaks with tongs and cook until the second side is golden brown, about 4 minutes longer.
Transfer the steaks to a clean wire rack set on a rimmed baking sheet and place in the oven. Cook until an instant-read thermometer inserted into the thickest part of the breast registers 150°F and the legs register 165°F, 5 to 10 minutes; remove the steaks to a second rack or a paper-towel-lined plate as they reach their final temperature. Season with salt and serve—or, for extra-crunchy fried steak, go to step 7.
Place the plate of cooked steaks in the refrigerator for at least 1 hour, and up to overnight. When ready to serve, reheat the oil to 400°F. Add the steaks and cook, flipping them once halfway through cooking, until completely crisp, about 5 minutes. Transfer to a wire rack set on a rimmed baking sheet to drain, then serve immediately.