Place the onion, garlic, beans, rocket and stock in a slow cooker. Gently mix until well combined. Cover and cook on low for 6–8 hours.
Purée the mixture until smooth, using a stick blender, food processor or blender. Stir the cream through. Cover and cook for a further 20 minutes, or until warmed through.
Meanwhile, make the basil pesto. Place the pine nuts, garlic and basil in