Clean the chicken and pat dry with paper towels. Prepare the coating by mixing potato starch, salt, and ground black pepper in a plastic container. Add the chicken, seal the container, and shake to coat the chicken evenly. Set aside.

Heat oil in a pan. Once hot, fry the chicken until golden brown on both sides. Remove and drain excess oil. For the sauce, mix minced garlic, vegetable oil, ketchup, gochujang, soy sauce, sesame oil, mirin, honey, Dijon mustard (optional), and apple cider vinegar in a mixing bowl.

Stir the sauce ingredients until well combined. Heat a pan and add the sauce mixture. Simmer until the sauce boils. Add the fried chicken.

Toss the chicken in the sauce until each piece is well coated. Serve on a plate, garnished with toasted sesame seeds and chopped green onions. Enjoy!