In a medium bowl, whisk together soy sauce, honey, and creamy peanut butter until smooth and blended. Add rice vinegar, grated fresh ginger, minced garlic, ground cumin, ground coriander, and optional red pepper flakes. Stir in sesame oil and fresh lime juice, creating a rich, glossy marinade.

Place chicken thighs in a large zip-top bag or bowl. Pour the prepared marinade over the chicken, ensuring each piece is well-coated. Seal or cover and refrigerate for at least 2 hours, ideally overnight.

Remove marinated chicken from the refrigerator to reach room temperature. If grilling, preheat the grill to medium-high, about 400°F. If roasting, preheat the oven to the same temperature.

For grilling, place marinated chicken on the grill and cook for 6-8 minutes per side until the internal temperature reaches 165°F. For roasting, arrange on a baking sheet, and roast for 35-40 minutes, basting occasionally with the marinade.

Once cooked, let the chicken rest for 5 minutes. Garnish with freshly chopped cilantro and toasted sesame seeds before serving hot with rice or vegetables.