01 - Arrange chicken thighs in an even layer at the bottom of the slow cooker insert.
02 - Whisk together soy sauce, honey, ketchup, rice vinegar, sesame oil, garlic, ginger, and red pepper flakes in a medium bowl until well combined. Pour the sauce evenly over the chicken.
03 - Cover and cook on low heat for 4 hours until chicken is tender and reaches an internal temperature of 165°F.
04 - Transfer cooked chicken to a cutting board and shred using two forks or cut into bite-sized pieces.
05 - Whisk cornstarch and water in a small bowl until smooth. Stir into the sauce remaining in the slow cooker.
06 - Return shredded chicken to the slow cooker and stir to coat. Cook on high heat for 15-20 minutes until sauce bubbles and thickens.
07 - Serve chicken over steamed rice, generously garnished with sesame seeds and sliced green onions.