Start a charcoal or wood fire or heat a gas grill or broiler. The fire should not be too hot, but the rack should be fairly close to the heat source, 4 inches or less. If necessary, you can pound the chicken slices lightly between 2 pieces of waxed paper so that they are of uniform thickness.
Brush the chicken pieces with the soy sauce and sprinkle it with pepper. Let the chicken marinate in the refrigerator for 1 hour or more.
Grill or broil the chicken very quickly; it should take no more than 3 to 4 minutes per side. Sprinkle with lime juice and sesame oil; serve hot or at room temperature.