In small bowl, whisk together soy sauce, hoisin sauce, vinegar, sesame oil and sugar. Set aside.
Core iceberg lettuce and soak in ice water for 10 minutes to help separate leaves. Carefully remove leaves from heads of lettuce one at a time; trim each leaf into a perfect circle using a pair of scissors. You should get about 12 nice lettuce cups out of each head, depending upon size and condition of lettuce.
Combine chicken, scallions and jicama with soy sauce mixture. Spoon about 3 tablespoons of the mixture into each lettuce cup. Garnish with pomegranate seeds.
Recipe by Chef John Beardsley, 415 Asian Restaurant and Lounge (San Francisco, CA)