Peel the onion and chop finely. Melt the butter in a saucepan and sweat the onion cubes in it. Mix with flour and curry paste or curry powder and sauté briefly.
Stir in 750 ml of water and the cream and bring to the boil. Stir in the vegetable stock and let the soup simmer for 10 minutes, stirring occasionally. Season to taste with salt and pepper.
Meanwhile, toast the flaked almonds in a pan without fat. Serve the soup and sprinkle with the flaked almonds and parsley.