In a separate bowl, mix together honey, onion, soy sauce, tomato paste, ketchup, cornstarch, garlic, and crushed red pepper. Pour over chicken in slow cooker and cook covered for 3 to 3-1/2 hours on LOW.
Meanwhile, heat water to boiling and add rice. Stir once, remove from heat and cover.
Stir chicken and sauce when ready to serve, and pour over rice on plates.
Sprinkle with sesame seeds and garnish with green onions.