Heat a large frying pan over medium high. Add sesame oil, then add pork and cook 2 min. Add mushrooms and cook, stirring often, until mushrooms are tender and pork is cooked. Stir in water chestnuts and zucchini and cook 1 min. Stir soy sauce with honey and cornstarch in a small bowl until cornstarch dissolves. Pour over pork mixture and stir until thickened. Turn off the heat and stir in chives. Spoon into lettuce leaves.