01 - Arrange chicken thighs in the bottom of the slow cooker, ensuring even distribution for consistent cooking.
02 - Whisk soy sauce, honey, ketchup, rice vinegar, sesame oil, garlic, ginger, and red pepper flakes in a bowl until fully incorporated.
03 - Pour sauce mixture over chicken, cover, and cook on LOW for 4 hours until chicken reaches internal temperature of 165°F and is fork-tender.
04 - Transfer cooked chicken to a cutting board, shred using two forks or cut into bite-sized pieces, and set aside.
05 - Combine cornstarch and water to create slurry, stir into remaining sauce in slow cooker, and return chicken to pot.
06 - Cook on HIGH for 20-30 minutes until sauce thickens and coats chicken. Serve garnished with sesame seeds and green onions.