In a 5- to 6-quart slow cooker combine Ham Broth, ham, potatoes, carrots, leeks, celery, garlic, pepper, and nutmeg. Cover and cook on low-heat setting for 8 to 10 hours or on high-heat setting for 4 to 5 hours. Gradually stir in oatmeal. Stir in kale and thyme. If on low-heat setting, turn to high-heat setting. Cover and cook for 30 minutes more.