In a large skillet over medium high heat add the pork, onion, garlic, and ginger saute this for 8-10 minutes.
Add soy, rice vinegar, peanut butter, sesame oil, and water and saute for another 5 minutes
Stir in the sriracha and green onions. Transfer to a serving platter with the lettuce leaves and a spoon to fill. Serve with more hot sauce for those who like it extra spicy.