1. Place a small pile of shredded Napa cabbage on a large serving plate. Place the rice wine, fish sauce, ginger, garlic, chili, sugar, and 1 tbsp lime juice in a screw-top jar and shake to combine (I just whisked in a bowl).
2. Using a sharp knife, cut the tuna into strips of even thickness. Sprinkle with remaining lime juice.
3. Brush a wide skillet or ridged grill pan with oil and heat until very hot. Arrange the tuna strips in the skillet and cook until just firm and light golden, turning them over once. Remove the tuna strips from the skillet and reserve.
4. Add the tomatoes to the skillet and cook over high heat until lightly browned. Spoon the tuna and tomatoes over the Napa cabbage, then spoon over the dressing. Garnish with fresh mint and serve warm.