Heat olive oil in a saucepan over medium high heat. Add the chicken, onions, ginger, garlic and vegetables. Season with salt and pepper. Cook until the chicken is browned, stirring frequently to break down the chicken, about 10 minutes.
Whisk together the ingredients for the sauce. If you're using fresh ginger, I recommend blending in the blender to make sure the sauce is smooth without any chunks of ginger.
Transfer the sauce to the skillet (leaving about 1/4 cup for serving, if desired) and cook for an additional 2-3 minutes to make sure the chicken mixture is well coated by the sauce.
To serve, scoop the chicken mixture on to the lettuce. Add peanuts, extra sauce and extra green onions, if desired.
Storage: Store any leftovers in an airtight container, with the chicken mixture and lettuce separate. The recipe will last about 3-4 days in the fridge.Make Ahead: The easiest part of the recipe to prepare in advance is the sauce. Just store it in the fridge when complete and it will be ready for the recipe. I would also recommend chopping the vegetables in advance, which can be a tedious part of this recipe if you choose to use all the vegetables I chose.Substitutes: For best results, follow the recipe as is. However here are some common substitutes that would work well in this recipe.
Ground chicken: You can substitute ground turkey, ground beef or even small diced chicken breasts for the ground chicken!
Vegetables: All the vegetables are optional. You can omit any or all of them or substitute with your favorites.
Soy Sauce: If you have a soy allergy, try tamari sauce, or liquid aminos, and you can't tell the difference in taste.
Peanut Butter: If you have a peanut allergy, you can substitute any nut butter or seed butter.