into 2-inch strips. Heat 1 Tbsp. oil in hot wok or large skillet over high heat. Add chicken and stir-fry 2 minutes; remove. Heat remaining 1 Tbsp. oil in same pan. Add lettuce; stir-fry 1 minute. Add chicken and teriyaki sauce mixture. Cook, stirring, until sauce boils and thickens. Remove from heat and stir in peanuts.