Whisk together soy sauce, sesame oil, lime juice, garlic powder, ground ginger, and chili flakes in a medium bowl. Add chicken thighs and toss until evenly coated. Marinate for at least 20 minutes at room temperature or refrigerate for up to 4 hours. Do not skip this step even if time is short.

Combine peanut butter, soy sauce, honey, rice vinegar, sesame oil, minced garlic, and grated ginger in a small bowl. Whisk until smooth. Add warm water one tablespoon at a time until the sauce reaches a pourable but not watery consistency. If the sauce thickens as it sits, stir in a few drops of warm water before serving.

Toss green cabbage, red cabbage, carrots, bell pepper, scallions, and cilantro together in a large bowl. Whisk lime juice, rice vinegar, sugar, and a pinch of salt in a small bowl, then pour over the vegetables and toss well. Let sit for 10 minutes. Drain excess liquid before assembling if needed.

Heat a grill pan or large skillet over medium-high heat. Add a small drizzle of neutral oil and cook the marinated chicken thighs 5 to 7 minutes per side until deeply golden and the internal temperature reaches 165 degrees F. Juices should run clear. Rest for 5 minutes, then slice thinly against the grain.

Warm tortillas in a dry skillet for about 10 seconds per side, or wrap them in a damp paper towel and microwave for 20 seconds. Warm tortillas are more pliable and less likely to crack when rolling.

Spread a generous spoonful of peanut sauce down the center of each tortilla, leaving about an inch of space around the edges. Drain slaw if needed and layer over the sauce. Top with sliced chicken and drizzle with extra peanut sauce. Garnish with cilantro and chopped peanuts if desired.

Fold the bottom edge up over the filling, fold in both sides firmly, then roll tightly away from you. Slice diagonally and serve immediately for the best texture and crunch.