Peel the celeriac and parsnip.
Cut the celeriac into medium-sized pieces and the parsnip into large slices.
Rinse the mushrooms and cut them into quarters. Fry them for 3 or 4 minutes in a pan with a little vegetable oil (or butter).
Put the vegetables in a large pot or casserole. Cover with the vegetable stock and coconut milk. Mix well, then add the bay leaves.
Bring everything to the boil.
Once the stock is boiling, add the mushrooms, cover and simmer over medium heat for 20-25 minutes.
Check the cooking with the tip of a knife, when it easily pierces the vegetables, you can stop the cooking.
Then add the flour or hazelnut powder, the spices (nutmeg, paprika, vanilla powder, salt and pepper) and the lemon juice and mix well.
You can enjoy this soup cold or hot. Just before serving, add 1 teaspoon of hazelnut oil, a few drops of lemon juice, freshly chopped hazelnuts and a few parsley leaves to each bowl.