Chop all vegetables. They will be blended together after cooking, however cutting them small will allow for faster cooking if that is desired.
Add all ingredients except for the optional toppings and salt and pepper to a slow cooker.
Mix well and allow to cook for approximately 6 hours on high.
Blend the soup using an immersion blender or a regular blender until it reaches a smooth consistency. Leave thick to use as a dip or spread. Add more vegetable broth to thin to desired soup consistency.
Taste the soup and season with salt and pepper as needed.