In a large bowl, whisk together soy sauce and cornstarch until smooth.
Add honey, tomato paste, diced onion, garlic and crushed red pepper.
Add chicken and bell pepper to sauce, toss to coat.
Transfer to slow cooker and cook on low for 4 hours. (Can leave up to 6 hours on low, chicken and red peppers will just be extra soft.)
Serve over rice and broccoli, as desired. Top with sesame seeds and green onion.
