For pork belly: Place pork belly in a large, nonreactive mixing bowl and add remaining marinade ingredients. Mix until thoroughly combined. Cover and refrigerate for 30 minutes. Spray grill with nonstick cooking spray. Grill pork belly for 4 to 5 minutes. Flip and continue to grill for 2 additional minutes. Remove from grill and set aside.
To assemble: Place a tablespoon or two of rice onto the center of a single red lettuce leaf and top with pork belly, green onions and sesame seeds. Wrap up and eat.