Clean the Brussels sprouts and leek and cut the leek into small pieces. Wash and chop the chilli pepper.
Heat the oil in a saucepan, sauté the leek and chilli pepper. Add Brussels sprouts and sauté. Then roast the curry powder in the pot and quench with the vegetable stock. Reserve some vegetable stock, mix with flour and add to the rest of the saucepan. Cook for about 20 minutes while stirring.
Finely puree the soup with a hand blender, add a splash of lemon juice, salt and pepper and the sour cream to taste.
Tip: If you like, you can top the soup with roasted almonds.