Begin by making the pouring sauce. In a large bowl, dissolve sugar in 1/2 cup warm water, then add soy sauce, rice wine vinegar, ketchup, lemon juice and sesame oil. Whisk together well. Then add in mustard and/or Sriracha to taste. Set aside or pop in the refrigerator until ready to use.

Combine olive oil and sesame oil and add to wok or large frying pan. Heat oil over high heat until it glistens, about one minute. Add chicken and saute until cooked through, then remove from the pan and cool. Keep oil in the pan, keeping it hot over a low flame.

Prep the stir fry sauce by mixing soy sauce, brown sugar, and rice vinegar in a small bowl.

Take pan that you cooked the chicken in (with the still-warming oil) and turn it up to medium-high heat. Add another tablespoon of olive oil to the pan, wait one minute, and then add garlic, onions, water chestnuts, mushrooms, and the stir-fry sauce you prepared earlier. Stir-fry everything until the mushrooms have cooked, about four minutes, then add in the chicken and stir until combined. Remove from heat.

Serve stir-fry with iceberg lettuce or nappa cabbage leaf wraps and top with pouring sauce.