1. In a bowl, combine the cornstarch, salt, and pepper. Toss the chicken pieces in the mixture until well coated.
2. Heat the vegetable oil in a skillet over medium-high heat. Add the chicken and brown on all sides, about 5-7 minutes. Transfer the browned chicken to the slow cooker.
3. In a separate bowl, whisk together the chicken broth, soy sauce, orange juice, hoisin sauce, brown sugar, minced garlic, minced ginger, and red pepper flakes.
4. Pour the sauce over the chicken in the slow cooker, ensuring all pieces are covered.
5. Cover and cook on low heat for 4-5 hours, or until the chicken is tender and cooked through.
6. Serve the chicken over rice, garnished with sliced green onions and sesame seeds.
Variations & Tips

For a gluten-free version, use tamari instead of soy sauce and ensure your hoisin sauce is gluten-free. If you prefer a milder dish, reduce the amount of red pepper flakes. For added texture, you can include chopped bell peppers or broccoli in the slow cooker during the last hour of cooking. To make it even more citrusy, add some orange zest to the sauce.