In a mixing bowl, combine soy sauce, sesame oil, lime juice, garlic powder, ground ginger, and chili flakes if desired. Add chicken thighs and marinate for at least 20 minutes.

In another bowl, mix creamy peanut butter, honey, rice vinegar, and sesame oil until smooth, adding warm water gradually to adjust consistency.

In a large bowl, combine shredded green cabbage, red cabbage, julienned carrots, diced red bell pepper, scallions, and cilantro. Dress with lime juice and rice vinegar, adding sugar and salt to taste.

Heat a grill pan over medium-high heat. Cook marinated chicken thighs for 5-7 minutes on each side until cooked through (internal temp 165°F). Let rest and slice.

Warm tortillas, spread peanut sauce, layer with slaw and chicken, drizzle additional peanut sauce, fold, and slice in half to serve.