In a large nonstick skillet coated with cooking spray, cook chicken in 1 tablespoon oil for 3 minutes; drain. Add the mushrooms, water chestnuts and ginger; cook 4-6 minutes longer or until chicken is no longer pink. Drain and set aside.
In a small bowl, whisk the vinegar, teriyaki sauce, soy sauce, garlic powder, red pepper flakes and remaining oil. Stir in the carrots, onions and chicken mixture.
Spoon onto lettuce leaves; sprinkle with almonds. If desired, fold sides of lettuce over filling and roll up.