Put the cubed chicken in a large bowl. Sprinkle with black pepper, garlic powder, and kosher salt and stir until evenly seasoned. Sprinkle with the cornstarch and stir to coat. Transfer the chicken to a greased or lined slow cooker.
In a small bowl, mix together honey, light soy sauce, brown sugar, hoisin sauce, sriracha sauce, sesame oil, rice vinegar, and minced garlic. Pour the sauce mixture over the chicken and stir to coat.
Cook on low for 3-4 hours. Start checking the temperature of the chicken after 3 hours and cook until the chicken reaches 165˚F. Or cook it on high for 1 1/2-2 hours and start temping the chicken after 1 1/2 hours.
Garnish with sliced green onions and sesame seeds. Serve over rice or noodles.