1. Preheat the grill to medium-high.
2. Prepare Ginger-Carrot Slaw. In a medium bowl, whisk together rice vinegar, 1 Tbsp. olive oil, 1 tsp. sesame oil, 1 tsp. soy sauce, and 1 tsp. grated ginger. Add carrots. In a small skillet, toast sesame seeds over medium-high heat, stirring frequently, until lightly browned, about 1 to 2 minutes. Toss with the carrot slaw and set aside.
3. Prepare the patties. Chop tuna into 1/2-inch pieces and place in the bowl of a food processor. Add 1 Tbsp. soy sauce, 1 Tbsp. olive oil, 2 tsp. sesame oil, egg white, 1 Tbsp. minced ginger, scallions, and garlic. Pulse to chop and mix, but do not process into a puree; mixture should be coarse. Form into 8 small patties.
4. Brush hot grill with vegetable oil. Place patties on the grill and cook for 1 to 3 minutes per side, or to desired degree of doneness (1 minute per side for rare, 2 for medium rare, 3 to 4 for medium). During the last minute of cooking, place the rolls around the edge of the grill, split sides down, to warm through.
5. Divide the spinach among the bottom halves of the rolls and top with a burger. Place some slaw on top of each burger followed by the top halves of the rolls. Serve immediately.
Source: fresh magazine May, June 2010