Heat oil in a large skillet over medium heat. Add chicken, garlic, onions, salt and pepper and stir occasionally, until chicken is cooked through. Add the carrots, zucchini, and green onions, cooking an additional 4-5 minutes or until vegetables are tender.
In a small bowl combine the sweet chili sauce, chunky peanut butter, and soy sauce. Stir until smooth. Add to the chicken and vegetables, stir until blended in and heated through. Add cilantro to taste. Spoon mixture into lettuce leaves and enjoy!