Watercress soup (Velouté de cresson)

1. In a pot, soften the diced onion in butter until translucent.

2. Add the diced potato, pour in the vegetable stock, season with salt and pepper and cook for about 15 minutes until the potato is tender.

3. Drop in the washed watercress (stalks and all) and cook together for just 2-3 minutes so it keeps its vivid green colour.

4. Blend silky-smooth with a stick blender.

5. Stir in the cream and just warm through (do not boil hard, so the colour stays).

6. Serve fresh and hot, adjusting the salt to taste.

Tip: Watercress (cresson) gives a lightly peppery, sharp-green flavour. The fresh green colour is key: cook it only briefly and warm the cream in gently. A drop of lemon juice lifts its freshness.