Szechwan White Cut Chicken With Spicy Peanut Sauce

• 1 green onion (whole)
• 475 ml water
• 400 gr chicken breasts
• 240 gr iceberg lettuce (shredded)
• 12 ml salad oil
• 10 ml vinegar (white)
• 10 ml soy sauce
• 7 ml creamy peanut butter
• 5 ml dry sherry
• 2 gr salt