Chicken Stir-Fry Wraps

1 1/2 lbs chicken breasts, halved horizontally and thinly sliced
salt and black pepper
2 T olive oil
1 large onion, halved and thinly sliced
1 large red bell pepper thinly sliced
3 cloves garlic, minced
1 1/2 tsp grated peeled fresh ginger
1/4 to 1/2 tsp red-pepper flakes (depends on how spicy you want it)
3 T soy sauce
3 T rice vinegar
1 1/2 tsp cornstarch, mixed with 1 T water
12-18 Boston lettuce leaves (about 2 heads)

1. Season chicken with salt and pepper. In a large skillet, heat 1 T oil over high heat. Add half the chicken; cook, stirring constantly, until opaque throughout, 2-4 min. Transfer to plate. Repeat with remaining chicken.
2. Add remaining 1 T oil to pan, along with the onion and bell pepper. Cook, stirring constantly, until onion is tender and golden, about 4 min (reduce heat if browning too quickly).
3. Reduce heat to medium; add garlic, ginger and red-pepper flakes; cook, stirring, until fragrant, 30-60 seconds.
4. Stir in soy sauce, vinegar and cornstarch mixture; remove from heat. Add chicken and any accumulated juices; toss to coat. Serve in lettuce cups.

Found on Martha Stewart.com under light and healthy recipes.