In a medium bowl, whisk together soy sauce, brown sugar, minced garlic, grated ginger, and sesame oil until smooth. Add green onions, black pepper, and chili flakes.

Slice chicken into thin strips and marinate in the mixture for at least 20 minutes or up to 2 hours.

Preheat a skillet over medium-high heat and add oil.

Cook the marinated chicken for 5–7 minutes until caramelized and fully cooked.

Serve hot, garnished with sesame seeds and green onions, alongside steamed rice.

Store leftovers in an airtight container in the fridge for up to 3 days.