Watercress soup with smoked salmon recipe

Ingredients

• 12 slices of good smoked salmon
• 250 g watercress (without large stems)
• 100 g very finely sliced potato
• 1 large shallot, finely chopped
• 50 ml olive oil
• 1 tsp creamed horseradish
• 50 ml double cream
• 1 l cold water
• 50 g fresh horseradish root
• 1 salt
• 1 pinch black pepper