Add the chicken to a bowl with the cornstarch. Stir until the chicken has been coated with the cornstarch. Cook the chicken in a large skillet on medium heat until it is golden brown. Place the chicken in a slow cooker.
Mix together hoisin sauce and soy sauce in a small bowl. Add brown sugar, garlic cloves, rice wine vinegar, sesame oils, ginger, crushed red pepper, and rice wine vinegar. Add to the chicken and cook in the slow cooker.
Turn the heat down to low and cook for 3-4 hours, or until the chicken is fully cooked. *Please see note
Serve with rice, garnished with sesame seeds, green onions and red pepper flakes.