Begin by cutting the chicken breasts into bite-sized pieces, ensuring they are uniform for even cooking.

In a large mixing bowl, combine all-purpose flour, cornstarch, garlic powder, white pepper, salt, and chicken stock powder. Whisk until fully blended.

Add the dry mixture to the bowl of chicken pieces, followed by a splash of water. Coat each piece thoroughly.

In a large frying pan, heat cooking oil over medium heat for about 5 minutes.

Carefully add the coated chicken pieces in batches, frying each for about 3-5 minutes until golden brown.

While the chicken is frying, whisk together gochujang paste, ketchup, and sesame oil in a medium bowl until smooth.

Once all chicken is fried and golden, toss it in the gochujang sauce until evenly coated. Serve hot garnished with sesame seeds.