In a small bowl, stir together the lime juice, fish sauce, sugar and garlic, until the sugar dissolves. Add the onion and let stand for 10 minutes, stirring occasionally.
Step 2
In a large bowl, toss together the chicken, cabbage, carrots, chilies, basil and cilantro. Pour on the red onion–dressing mixture and toss. Toss in half of the peanuts, then transfer to a serving bowl. Sprinkle with the remaining peanuts and serve with lime wedges on the side.