Shred the red cabbage thinly using a mandoline or sharp knife. Julienne the mango into matchsticks. Soak the sliced red onion in cold water for 5 minutes to mellow its bite, then drain well. Chop the cilantro.

In a small bowl, whisk together the lime juice, olive oil, honey (if using), salt, and pepper until emulsified.

In a large bowl, combine the shredded cabbage, mango, red onion, and cilantro. Pour the dressing over the top and toss well to coat evenly.

Transfer the slaw to a rustic serving bowl. Garnish with lime wedges and toasted coconut flakes if desired. Serve immediately or chill for later.