Prepare grill and ignite charcoal or preheat broiler; preheat oven to 350'F. Trim all fat from chicken breasts and cut lengthwise into 1/2" wide strips; set aside.
In small bowl whisk together soy sauce, sesame oil, lemon juice and sugar; divide in half. Toss half the soy sauce mixture with the chicken strips and reserve half for the salad dressing.
Thread chicken on skewers and grill over medium coals about 4 minutes per side, or until done.
Meanwhile, toast almonds on a dry cookie sheet at 350'F. for five minutes, or just until lightly browned. Peel and cut up mango; drain, rinse and drain water chestnuts. Wash and tear lettuce into bite-size pieces. Combine almonds, mango and lettuce in large bowl. When chicken is cooked, add to salad and toss with remaining soy sauce mixture.