In a bowl, stir the orange marmalade, ketchup, brown sugar, vinegar, soy, ginger, and red pepper flakes together until combined. Pour over the chicken. Cook on low for 4 hours or on high for 2 hours.
Mix the water and cornstarch together. Pour mixture into the crockpot during the last 10 minutes of cooking, replace the lid so it comes up to a slight boil and thickens. (If you are cooking on low, switch over to high for the last 10 minutes).
Serve over rice and garnish with white sesame seeds and green onion.
Pro tip: As you’re serving your chicken there will be some sauce left at the bottom of your slow cooker. Don’t forget to spoon this out and drizzle it over your chicken and rice!