Whisk together the first 5 ingredients and set aside. Finely chop the water chestnuts, mushrooms and scallions, combine and set aside.
Heat pan to med-hot, add the vegetable oil, and put ground meat in pan breaking it up as it cooks. If you have a non-stick pan, you won't need oil. Cook until 1/2 of the pink is gone, about 5 minutes. Now add the vegetables and continue cooking for 3-5 more minutes until meat is done.
Add the soy sauce mixture to the pan and continue stirring and simmering for about 5 minutes. Taste the mixture and adjust to your liking-you may want to add more of the sauce ingredients. Scrape the pan to get all the bits up off of the bottom.
While meat is simmering, combine the final 7 ingredients to make a dipping sauce. Whisk together and taste, then adjust to your liking. The sauce should be sweet and tangy and spicy if you like.
Remove the outer leaves of the ice burg lettuce then make 2 cuts, one to each side, leaving the center section (use for a salad later) You will use these as "wraps."
Serve the meat and lettuce separately. Put spoonfuls of meat in the center of a lettuce leaf, spoon some sauce on and roll up to eat.