1. Heat the vegetable oil in a large saucepan and saute the garlic and onion together for 3 to 4 minutes until softened. Add the courgettes and cook stirring for 2 more minutes. 2. Add the stock to the saucepan and bring to the boil. Lower the heat and add the lettuce and parsley. Cover and simmer for 20 minutes. 3. Blend the soup in a liquidiser or food processor until smooth. Return to the saucepan and add the milk and blended cornflour, then heat gently until thickened slightly. Season with the nutmeg salt and pepper according to taste. 4. Serve one portion piping hot in a warmed soup bowl. Alternatively the soup may be cooled and served chilled. 5. To freeze the remaining soup cool quickly and divide between three rigid containers. Seal label and freeze for up to three months. Defrost and re-heat gently to serve. Preparation 10 minutes. Cooking 30 minutes.