Pat chicken dry with paper towels. Poke holes with a fork, cut thick parts to flatten, and season both sides with salt and pepper. Coat with potato starch.

Prepare lettuce to match chicken size. Slice green onion into thin strips and soak in water. Mince remaining green onion and ginger.

Place lettuce on chicken, roll tightly, secure with toothpicks, and coat with potato starch.

Heat salad oil in a pan, place chicken rolls seam-side down, and cook until browned. Cover and steam on low heat for 4 minutes. Remove and cool.

Wipe pan clean, sauté minced green onion and ginger, add sauce ingredients, and simmer for 2 minutes.