Instructions

1. 1

   Heat the butter in a heavy saucepan over a medium heat and add the leeks. Press a piece of damp greaseproof paper on top, cover, and cook, shaking gently from time to time, for 15 minutes, or until the leeks are softened and golden.

   
   

2. 2

   Add the potatoes, celery, and stock, and season with salt and pepper. Bring to the boil, stirring, then cover and simmer for 30 minutes, or until the vegetables are tender.

   
   

3. 3

   Remove the pan from the heat and leave to cool slightly, then process in a blender until very smooth, in batches if necessary. Season to taste with salt and pepper and allow the soup to cool completely before stirring in the cream. Chill for at least 3 hours before serving.

   
   

4. 4

   To serve, pour into serving bowls, stir in a little cream, and sprinkle with chives and black pepper.