Grease the slow cooker and place all of the ingredients inside EXCEPT for the parmesan cheese and the cream. Place the lid on and cook either on low heat for 6-7 hours or high heat for 3-4 hours.
After cook time is up, puree the soup using either an immersion blender or a classic blender. If using a classic blender, blend it up in batches and leave room for the steam to escape while blending.
Once the soup is pureed and smooth, place it back in the slow cooker and stir in the parmesan cheese and the cream. Taste and season with any additional seasonings you think it needs. At this point, I usually add more salt and pepper, more basil and some paprika.
Place the lid back on with the heat at low for 25-30 more minutes, until the soup is heated through. Then serve immediately.
Refrigerate any leftover soup. To reheat it, just place the desired amount in a saucepan over med-high heat and simmer for 5 or so minutes, until heated through. If I have a good amount of soup leftover, then sometimes I'll use the leftover soup as a pasta sauce for an easy dinner option.
