Combine the soy sauce, honey, ketchup, minced garlic, dried basil, oregano, red pepper flakes, and black pepper in a large bowl to prepare the sauce.
Arrange the chicken thighs, halved baby red potatoes, and baby carrots in the slow cooker. Pour the prepared sauce evenly over the ingredients.
Cover and cook on low heat for 7–8 hours, or on high heat for 3–4 hours. Baste the chicken with the sauce every hour for enhanced flavor.
Add the green beans to the slow cooker during the final 30 minutes of cooking.
(Optional) Preheat your oven to broil. Place the cooked chicken thighs on a baking sheet, skin-side up, and broil for 3–4 minutes, or until the skin becomes crispy.
Serve immediately, pairing the chicken with the potatoes, carrots, and green beans. Sprinkle with chopped parsley for garnish, if desired.