Chop the chicken to bite size pieces.
Place the chicken in a bowl and season with salt, pepper, garlic, and egg. Let sit for at least an hour in the fridge to brine.
After brining, add potato starch and water to the brined chicken then mix thoroughly. Add water gradually and check for consistency of the batter: Make sure it is not too thick that you can lift the bowl and not too thin that it’s too runny.
Heat up the oil until 350F, and fry the chicken in batches for 5-6 minutes each.
Remove the chicken from the oil and let rest for a couple of minutes.
Smash the chicken to create air holes. Heat up the oil to 375F and place the chicken back for the second fry. Fry the chicken for 2 minutes.
Remove the chicken from the oil and let cool in a wire rack.
Make the sauce by combining gochujang, ketchup, soy sauce, sugar, garlic, and corn syrup.
Simmer the sauce on low for a couple of minutes then quickly toss the fried chicken in the sauce.
Plate, top with sesame seeds, and serve immediately. Enjoy!