Lettuce Soup

Method

1. Separate 150 g of cos lettuce, wash the leaves well in cold water to remove grit, shake dry and shred them across into ribbons about 1 cm wide. Keep the pale heart leaves aside from the tougher dark outer ones.
2. Warm 1 tbsp of olive oil in a small heavy saucepan over low heat. Add 50 g of thinly sliced leek and 1 clove of sliced garlic with a pinch of the salt and sweat gently for 5 minutes, stirring, until soft and translucent but not coloured — no browning, or the soup loses its clean green flavour.
3. Add 100 g of diced potato and turn it in the oil for 2 minutes so the edges soften and take on the flavoured fat.