In a large mixing bowl, combine the diced mangoes, shredded cabbage, grated carrot, sliced red bell pepper, sliced red onion, and chopped cilantro. Toss well to mix everything evenly.
In a separate small bowl, whisk together the lime juice, honey (or maple syrup), sesame oil, salt, and pepper until well combined.
Pour the dressing over the mango and vegetable mixture. Toss gently to coat everything evenly with the dressing.
If using, sprinkle chili flakes or chili powder over the slaw and toss once more.
Let the slaw sit for 5 to 10 minutes at room temperature to allow the flavors to come together before serving.
Serve chilled or at room temperature as a side dish. Garnish with extra cilantro and a lime wedge if desired.