In small bowl, mix onion, honey, soy sauce, ketchup, oil, sesame oil and garlic. Set aside.

Place chicken in 4- to 5-quart slow cooker. Pour honey mixture evenly over chicken.

Cover; cook on Low heat setting 4 hours.

With slotted spoon, remove chicken from slow cooker, leaving sauce in cooker. In small bowl, stir cornstarch into water until dissolved. Pour into slow cooker; stir to combine with sauce. Cover; cook sauce on High heat setting 10 minutes longer or until sauce has thickened.

While sauce is cooking, shred chicken with 2 forks.

Return shredded chicken to slow cooker; toss with sauce. Sprinkle with sesame seed before serving.