A wonderful, luminous-green soup. If you like, simplify the method: instead of basil oil, finish with shredded basil or mint and a drizzle of oil; and miss out passing it through a sieve – it’ll be less smooth, but still delightful.
- 2 tbsp olive oil
- 20g unsalted butter
- 3 leeks, trimmed and finely sliced
- 4 shallots, peeled and finely sliced
- 2 garlic cloves, peeled and finely sliced
- 2 sticks celery, finely sliced
- 2 bay leaves
- Salt and white pepper
- 800g podded peas
- 1 litre water
- 4 heaped tsp crème fraîche, to serve
For the basil oil
- 2 bunches basil, leaves picked
- ½ clove garlic
- About 100ml olive oil
First make the basil oil:
- Put the basil leaves, garlic, some salt and pepper in a small food processor bowl
- Turn on the machine and add the oil in a slow stream until you have a runny purée consistency. The oil will keep in the fridge for a few days.
Now the soup:
- Heat the oil and butter in a large pot
- Add the leeks, shallots, garlic, celery, bay leaves, some salt and white pepper
- Sauté them over a low heat for 20 minutes, stirring occasionally – it is important that you give it at least this amount of cooking time, to allow the natural sweetness of the vegetables to come out; make sure, though, that they do not take on any colour.
- Add the peas and water, bring to a gentle boil and cook for five minutes, just lightly to cook the peas.
- Remove from the heat, remove and discard the bay leaves, and use a blender to process the soup as fine as you can.
- Transfer the soup to a fine sieve, then take your time to pass it through thoroughly – use the back of a ladle to press the mashed-up vegetables through the sieve, rubbing them vigorously on the inside of the sieve. You want to end up with a totally dry pulp in the sieve, which you can then discard.
- Transfer the soup to a clean pot and reheat gently.
- Taste and adjust the seasoning.
To serve, pour the soup into serving bowls and finish with a drizzle of basil oil and crème fraîche on top.