Place a pan over a low heat, add oil, courgettes and leek then cook for 5 minutes until soft.
Add the garlic to the pan and cook for a further minute.
Add vegetable stock and ProZero, bringing to the boil and simmer for 2 minutes.
Add the basil, salt and pepper.
Using an electric hand-held blender, blend until smooth.
For extra crunch, top with Mini Crackers.
ProZero is a food for special medical purposes and must only be used under medical supervision.