Yummy lettuce wraps!

This is one of our favorite gluten-free items, especially because it is hard to find restaurants that will prepare chinese food with a gluten-free soy sauce. PF Changs in Salt Lake does and so does their relative Pei Wei in Bountiful. But the one in Bountiful doesn't serve our favorite lettuce wraps so when my friend Jen told me she had a recipe that was really close we were very excited. Like most Chinese food it does involve some chopping but if you have anything like one of these little choppers then it is a snap.
Special sauce:
1/4 c sugar 1/2 C water 2Tb. Soy sauce (gluten free if it is an issue for you)
2Tb Rice vinegar 2 Tb Ketchup 1 Tb Lemon Juice
1/8ts sesame oil 1/2Tb Chinese hot mustard or garlic chili sauce(youcan find these in the chinese food section) and 2 ts water
Filling:
3Tb Veg oil 2 Chicken breasts skinless boneless
1 C Water Chestnuts 2/3C Staw mushrooms(canned)
3Tb Green onion 1 clove garlic minced
Stir Fry Sauce:
2Tb Soy sauce 2Tb Brown sugar 1/2 ts Rice vinegar
1. Make sauce by dissolving the sugar and 1/2C water in small bowl. Add the soy, rice vinegar, ketchup, lemon juice,and sesame oil. Mix well and refridgerate this sauce while you prepare the remaining food. Combine theh 2ts water and Chinese hot musard and set this aside as well.
2. Prepare the filling by first dicing the mushrooms, green onion, and water chestnuts. Next in 2 tsp oil saute chicken until done. I also use left over chicken for this and it is great. While chicken cools mix the stir fry sauce items. Dice chicken when cool. Add remaining oil to hot pan. Stir in chicken, mushrooms, onion, garlic and water chestnuts. Pour stir fry sauce over the mix and saute for a couple of minutes. Place in a dish or on a bed o f maifun rice noodles.
3. Serve with a side of lettuce cups which are made by slicing the top off the head and cutting through the middle. Lay one half down and lift off cups.
4. Mix special sauce with a small amount of hot mustard and chili paste(according to your taste). Place filling in cups. Pour sauce over filling inside wrap and fold like a taco.