Peel potatoes and cut into 1 cm cubes. Clean the leeks, wash and cut into 1 cm wide rings.
Heat 2/3 of the butter in a large soup pot, brown the potatoes, add the leeks and sauté for 3 minutes until soft. Add clear soup, bring to a boil and simmer on low heat for about 8 minutes.
Remove the meat from the bone, cut into 1 cm cubes. Peel the banana and mash it with a fork. Add to the soup with the meat and stir. Simmer at low temperature for another 5 minutes.
Add whipped cream, bring the soup to a boil briefly, season with Tabasco, salt, curry and juice of one lemon.