Put the leeks or onion in the hot oil cover and sweat gently for about 10 minutes, until soft.

Add the potato and stock. Bring to the boil, then simmer for about 10 minutes, until the potato is almost cooked. Add the cubed cucumbers and shredded lettuce, return to the boil and simmer for a further 4 minutes.

Purée everything in a blender and stir well. Stir in the cream or crème fraîche and season with salt and pepper. Leave to cool completely, then chill for a couple of hours.

Meanwhile, make the croûtons. Heat the oil in a frying pan over a medium-high heat. Add the bread and fry, turning often, for a few minutes, until golden brown. Leave to cool.

Serve the chilled soup topped with a swirl of cream or crème fraîche, chopped chives and the croûtons.


  • 50g oil
  • 2 leeks, trimmed (white and pale green part only), washed and sliced, or 1 large onion, sliced
  • 1 large, floury potato (about 250g), peeled and cut into large


  • 1 litre vegetable stock
  • 2 cucumbers, peeled and cubed
  • 2 Little Gem or butterhead lettuces, washed and shredded
  • 3 tablespoons double cream or crème fraîche, plus a little extra

To finish

  • Sea salt and freshly ground black pepper

For the croûtons

  • 4 tablespoons rapeseed or olive oil
  • 4 slices of bread, crusts removed, cut into cubes

to finish

  • Chopped chives