Begin by finely shredding the green and purple cabbages using a knife or mandoline. Grate the carrots and slice the red bell pepper into thin strips. Chop the green onions, reserving some for garnish. Combine all vegetables in a large mixing bowl.

In a small bowl, whisk together sesame oil, rice vinegar, soy sauce, and honey until well combined and emulsified.

Pour the dressing over the shredded vegetables and toss gently to coat. Let the slaw marinate for at least 10 minutes.

After marinating, toss the slaw again, check for seasoning, and garnish with reserved green onions and cilantro before serving.