There are a few different ways you can do this. In this recipe, we pull out all the stops with a three-step method. We use a slurry made of cornstarch and heavy whipping. A normal cornstarch slurry is made of cornstarch and cold water, but using cream instead of water adds another layer of thickening powder (and also rich flavor!). And because of the potato in this soup, if you want it even thicker, you can puree two cups of it in a blender and stir it back in. Or simply use a potato masher to partially mash the soup when it’s done cooking.