Add onion/celery to a large pan with big dollop of olive oil and some white wine vinegar and simmer on a gentle heat
Add courgettes, potato and garlic and allow to sweat while stirring for a few minutes
Add salt and pepper to taste and the nutmeg
Add the stock and bring to the boil
Cover and simmer on a low heat for 20 minutes until the ingredients are soft and pulpy
Either put through a blender, or stir with a sharp knife to blend manually.
Add the cheese and stir in thoroughly.
Serve with salad and crusty white bread