1. Place the boneless, skinless chicken thighs in the bottom of your slow cooker. In a medium bowl, whisk together the low-sodium soy sauce, honey, rice vinegar, grated fresh ginger, minced garlic, sesame oil, and black pepper until well combined. This is your flavorful teriyaki sauce.

2. Pour the prepared teriyaki sauce evenly over the chicken thighs in the slow cooker. Ensure the chicken is mostly submerged or coated by the sauce.

3. Cover the slow cooker with its lid. Cook on the LOW setting for 6-8 hours or on the HIGH setting for 3-4 hours. The chicken should be very tender and easily shreddable with a fork when done.

4. About 30 minutes before the end of the cooking time, in a small bowl, whisk together the cornstarch and cold water until a smooth slurry forms. This will be used to thicken your sauce.

5. Stir the cornstarch slurry into the slow cooker with the chicken and sauce. Add the broccoli florets, sliced carrots, and sliced red bell pepper to the slow cooker. Gently stir to combine, ensuring the vegetables are somewhat submerged in the sauce.

6. Recover the slow cooker and continue to cook for another 20-30 minutes on HIGH, or until the sauce has thickened to your desired consistency and the vegetables are tender-crisp. The chicken should be fall-apart tender.

7. Once cooked, use tongs or a slotted spoon to remove the chicken and vegetables. You can shred the chicken directly in the slow cooker or on a cutting board if desired. Serve hot over rice or noodles, garnished with sliced green onions and sesame seeds.