Remove the skin from the duck and discard. Thinly sliced the duck. Sprinkle with the 5 spice powder and toss to coat.
Heat oil in a wok or a large skillet. Add duck and stir fry for 3 minutes.
Add onion, mushrooms and celery. Stir fry until vegetables soften and start to change color, about 3-5 minutes. Add pear, water chestnuts and salt. Stir to combine.
Add honey, vinegar and soy sauce. Stir to combine. It will take about 1 minute for the sauce to come to a boil.
Add bok choy and bean sprouts. Cook on high until bok choy wilts, about 2 minutes.