Cutting the mayonnaise brings out the sweet flavor of Napa cabbage and makes this slaw low in fat. Substitute malt vinegar for rice vinegar, if you like.
In a large bowl, toss together cabbage and carrots. In a small bowl, combine sugar, vinegar, sesame oil, and soy sauce. Stir until sugar dissolves, then pour over cabbage mixture. Toss until slaw is coated and top with mint leaves.
Prep your ingredients a day ahead but wait to dress the slaw until just before serving.