Use a 6-quart slow cooker. Place the vegetables into your slow cooker and add salt and pepper. Stir in broth.
Cover, and cook on low for 7-8 hours, or until the garlic mashes easily with the back of a spoon. Use a potato masher (or hand-held immersion blender) to mash a few of the potatoes to thicken the broth. Stir in heavy cream. Cover, and cook on high for 20 minutes, or until hot.