If your chicken is not cooked, cook it first in a skillet over medium heat with salt and pepper until fully done. Let it rest for a few minutes, then shred or chop into small pieces.
In a bowl, combine peanut butter, soy sauce or tamari, grated ginger, minced garlic, lime juice, and sesame oil. Stir until thick and smooth. Add warm water one tablespoon at a time until the sauce loosens and becomes creamy.
Taste the sauce and adjust if needed. Add a little more lime juice for brightness or soy sauce for saltiness.
Carefully separate the cabbage leaves. Trim the thick bottom stem slightly if it feels too stiff to fold.
Lay a cabbage leaf flat. Add a portion of chicken in the center, drizzle with peanut sauce, and top with optional carrots, green onions, or crushed peanuts.
Fold the sides inward and roll tightly like a wrap. Alternatively, fold in half and eat like a taco.
Serve immediately for best texture.