Wrap the beetroot in aluminum foil and cook in the oven at 180 ° C for about 45-60 minutes.
In the meantime, peel and roughly dice the potatoes. Wash the lemon with hot water and rub the peel with the grater. Squeeze the lemon. Cook the potato cubes in the poultry stock for about 20 minutes until soft.
Peel and roughly dice the beetroot and add to the potatoes in the stock. Bring to the boil briefly and purée finely with the blender.
Add the lemon peel to the soup. Season to taste with wasabi, 3 tablespoons of lemon juice, salt and pepper. Fold in the whipped cream to taste.
Since wasabi is very hot, be careful with the seasoning and better season it.