In a small bowl, whisk together honey, garlic, soy sauce, oregano and ketchup.
Add the chicken thighs, potatoes, carrots and onions to a 4-6 quart slow cooker.
Pour the honey garlic sauce mixture evenly on top.
Cover the slow cooker and seal the lid. Cook on a LOW setting for 6-8 hours or on HIGH for 3-3 ½ hours (see note).
About 20 minutes before serving, add the green beans to the slow cooker and optional cornstarch slurry to the sauce.
Re-seal the lid and cook for 15-20 minutes more until the green beans are tender and the sauce is starting to thicken.
Remove the chicken and vegetables to serving plates using a slotted spoon. Optional: Broil the chicken thighs for 2-3 minutes to brown the skin.
Drizzle sauce on top of chicken and vegetables. Garnish with optional minced parsley.