For the burgers:

1. Preheat barbecue to medium.
2. Crush plain rice cake into fine crumbs in a resealable zip-top bag. Pat dry thawed shrimp and finely mince.
3. Whisk tamari and sesame oil with ginger, cornstarch and garlic cloves in a medium bowl. Add shrimp and ground pork. Gently mix together until combined. Stir in rice cake and chopped cilantro. Shape into four patties, about 1/2 inch thick.
4. Oil grill. Barbecue patties, lid closed, until cooked through, four minutes per side.

For the cabbage slaw:

1. Toss napa cabbage and grated carrot with white-wine vinegar and granulated sugar. Let stand for 30 minutes.

To assemble: Top four plain rice cakes with four Boston lettuce leaves (optional), burgers and cabbage slaw. Drizzle with slaw liquid. Garnish with more cilantro, if desired.