Insert chicken into the crockpot and sprinkle salt and pepper on each side.
In Medium sized bowl combine ketchup, honey, soy sauce, ketchup, vegetable oil, garlic, diced oinion, and red pepper flakes. Pour over the chicken in crock pot.
Cook on low 3-4 hours or high for 1 1/2 to 2 hours.
When done, remove chicken and cut it into chucks. Before returning chicken to crockpot, combine cornstarch in some water and whisk it into the crockpot to thicken it up a bit. Throw the chicken back into the crockpot to re-coat with sauce.