Pat pork chops dry and trim any excess fat cap. Rub all over with Dijon mustard and season both sides with 1 teaspoon of all-purpose seasoning.
In a shallow bowl, combine the flour, cornstarch, and remaining 2 teaspoons of all-purpose seasoning. In a second bowl, beat 2 large eggs until smooth.
Coat each chop in the flour mixture, dip into the egg letting the excess drip off, then return to the flour and coat evenly. Press lightly and shake off excess.
Place coated chops on a plate and let sit for 10 minutes.
Add about 1 cup of oil to a 10-inch cast iron skillet, enough to come up about ¼ inch. Heat over medium heat, bringing it up to temperature gradually. The oil is ready when a pinch of flour sizzles steadily or it hits about 350°F.
Fry pork chops for 3 to 4 minutes per side, until golden brown. Flip once and don't overcrowd the pan. Adjust heat as needed to maintain a steady sizzle.
Transfer to a clean wire rack and rest a few minutes before serving.
Notes
Resting the coated chops for 10 minutes is what helps the breading stay on during frying.
Use a wire rack instead of paper towels for resting cooked chops so the bottom crust stays crisp.
For thicker chops, add 1 to 2 minutes per side.
Pork chops are safely cooked when the internal temperature reaches 145°F. For best results, use a quick-read thermometer to check the internal temperature.