- Marinate the chicken breast with salt, white pepper, and soy sauce for 30 minutes.
- Combine all ingredients for the Nanban sauce and set aside.
- Coat the chicken with cornstarch and fry in a hot pan until golden brown on both sides and cooked through.
- Add the chicken, shredded cucumber, and sweet onion to the Nanban sauce, and refrigerate for 2 hours before serving.