Add Tomatoes and next 7 ingredients (through Broth) into slow cooker.
Cook LOW for 4 Hours
Prepare "Roux" by melting Butter in sauce pan.
Add flour and slowly whisk in 1 cup Heavy Cream
Add "Roux" and Parmesan Cheese to Slow Cooker and stir.
Cook LOW for ½ Hour
Serve, top with Basil and Parmesan.