Add everything, except the cheddar and parsley, into a large slow cooker and place on low heat. Cook for 2 hours then remove half of the soup and place it into a blender. Blend until smooth and creamy then add it back into the slow cooker and stir.
Turn the slow cooker to the warm setting. When ready to serve add half of the cheddar cheese and the 1 cup of parsley into the slow cooker and stir. Serve into individual bowls, then top each with 1/4 cup of cheese. Serve.