If you are using whole artichokes, trim them, removing the outer leaves and hairy choke, keeping only the cup-shaped bases. Chop and drizzle a tablespoon of lemon juice to avoid discolouration.
Toss in a large pot the artichoke hearts, leek, onion and olive oil and cook until softened (about 8 minutes)
Add in the vegetable stock, potato and dill, another tablespoon of lemon juice, then bring to the boil and simmer for 20 minutes.
Remove from heat, let the soup get to room temperature and use a food processor to make a purée and get the wonderful velvety texture. Reheat and enjoy!