Remove and discard stems from mushrooms.
Then chop the mushroom caps.
Chop Napa cabbage keeping leaves and stems separate.
Lightly coat a wok or skillet with cooking spray and place over med-high heat.
Add turkey and then stir-fry until no longer pink, about 3-4 minutes.
Remove turkey from the wok and set aside.
Lightly recoat the wok with cooking spray.
Add chopped cabbage stems and onion; stir-fry until tender.
Stir in Hoisin sauce, soy sauce and five-spice powder.
Add cabbage leaves, mushrooms and water chestnuts; stir-fry for about 1 minute.
Add cooked turkey back into the skillet and stir-fry until well combined and heated through, about 2 more minutes.
Place 3 lettuce leaves on each on each of the 4 plates.
Divide mixture into 4 portions.
Then divide those portions into thirds and spoon into the lettuce leaves.
You can add dipping sauces such as Chinese hot mustard, soy sauce and chili sauce to add a little more zip.
Ready in 30 min.