I bought some lovely young fennel from Tony Booth, who has now moved out of Borough Market to the food market at Tower Bridge. As well as the bulbs, I've also used the stalks and fern in this soup and shredded the stalk to make a salad garnish – and just one stem of fennel will be enough for 4 good servings with the peas.
1tbsp vegetable or corn oil
1 small onion, peeled and roughly chopped
1 stem of baby or young fennel (or a couple if they are small)
1.2 litres vegetable stock
Salt and freshly ground black pepper
350g freshly podded peas (or frozen ones will do)
1tsp cider vinegar
1tbsp rapeseed oil
Cut the fennel bulb away from the stalks and finely shred it with a sharp knife or on a mandolin and put to one side. Separate the ferns from the stalks and just keep a few of the ferns for garnish. Roughly chop the stalks, then heat the oil in a pan and gently cook the onion and stalks for 3-4 minutes, stirring occasionally until soft. Add the stock, season and simmer gently for 10-12 minutes.
Reserve about 60-70g of the peas and cook in boiling salted water with a little sugar, then drain, cool under the tap and mix with the shredded fennel. Add the rest of the peas to the soup and simmer for another 6-7 minutes or until they are tender (frozen peas will only need a couple of minutes once they come back to a simmer).
Blend in a liquidiser until smooth, then taste and adjust the seasoning. Pass through a sieve if you wish (some blenders do a better job than others) then leave to cool and adjust the consistency with a little more stock if necessary.
To serve, mix the cider vinegar and rapeseed oil with the peas, fennel and a few ferns and season. Pour the soup into shallow soup bowls and pile the pea and fennel salad up in the centre.