Begin by preparing the chicken thighs. Trim any excess fat and season with salt and pepper.
In a mixing bowl, combine the honey, soy sauce, garlic, and ginger. Mix well to create a sauce.
Place the chicken thighs in the slow cooker and pour the honey garlic sauce over them, ensuring they are well coated.
Add the broccoli, bell peppers, and carrots to the slow cooker, distributing them evenly around the chicken.
Cover the slow cooker and cook on low for 4 hours until the chicken is tender and fully cooked.
Once the cooking time is complete, carefully remove the chicken and vegetables. Set them aside on a serving platter.
In a small bowl, mix the cornstarch with cold water to create a slurry. Stir it into the sauce in the slow cooker. Turn the cooker to high and let it thicken for about 10 minutes.
Once thickened, pour the sauce over the chicken and vegetables.
Garnish with sesame seeds and chopped green onions if desired, and serve.