Whisk all sauce ingredients together in a small bowl; set aside.
Prepare bell peppers and shallots in a bowl; set aside.
Heat oil in a large wok or skillet over medium high heat. Add chicken, and cook, breaking up with the back of your spoon until fully cooked through. Transfer to a bowl on the side.
Re-heat wok or skillet, add more oil if needed. Add bell peppers and shallots, and cook 4-6 minutes until peppers are soft and slightly charred. Now add sauce, 2 green onions, chicken, and fresh basil to skillet, toss to combine and cook another few minutes until basil is wilted.
Spoon into lettuce cups, top with remaining green onion and cilantro, and enjoy!!