Roughly chop the onion and celery and add to a saucepan with the olive oil, bay leaf and salt and pepper.

Cook on a medium heat for 5 minutes stirring regularly.

Slice the garlic.

Remove the larger stalks from the watercress and roughly chop.

Peel and and roughly chop the potatoes and add to the pan along with the garlic and watercress stalks.

Cook for 2 minutes then add the vegetable stock and simmer on a medium heat for 25 minutes.

Remove the bay leaf then add the watercress and cream and cook for a final 2 minutes before blitzing with a stick blender.

Finally, place the hazelnuts in a dry frying pan and toast on a medium heat for 2-3 minutes until they stat to turn golden brown.

Remove from the pan, allow to cool then roughly chop.

Serve the soup with some hazelnuts scattered on top and a few drops of lemon juice.