Season both sides of chicken with lightly with salt and pepper, place into crock pot.
In a small bowl, combine honey, soy sauce, onion, ketchup, oil, garlic and pepper flakes. Pour over chicken.
Cook on low for 3-4 hours or on high 1 1/2 – 2 1/2 hours, or just until chicken is cooked through.
Remove chicken from crock pot to a cutting board.
In a small bowl, dissolve 4 teaspoons of cornstarch in 6 tablespoons of water and pour into crock pot. Stir to combine with sauce. This will thicken the sauce.
Replace lid and cook sauce on high for ten more minutes or until slightly thickened.
Meanwhile, cut chicken into bite size pieces, then return to crockpot and toss with sauce. Let heat back up for about 15 minutes before serving.
Sprinkle with sesame seeds and serve over rice or noodles.