Spray crock pot with non-stick cooking spray.
Season chicken pieces with salt & pepper and place in crock pot.
In a bowl, combine honey, soy sauce, onion, ketchup, oil, garlic and pepper flakes.
Pour over chicken.
Cook on low for 3 hours, open and stir, and set on high for last two hours.
Remove chicken with a slotted spoon, leaving the juices behind.
Dissolve 3 heaping TBSPs of cornstarch in 1/4 cup of cold water. This should resemble a thin paste. If too thick, add a bit more water and stir until dissolved.
Pour sauce into crock pot and stir until dissolved and sauce starts to thicken. Close lid and heat on high for another 5 to 10 minutes. Sauce should be nice and thick.
Shred chicken with 2 forks and add back into to crockpot and stir to coat with sauce.
Sprinkle with sesame seeds when put in serving dish or on plates.