An intense, rich West African soup, but overlaid with colonial elegance. Serve cold as a first course to 6.
Interestingly, it is known to Dutch reader Reni Kistel as "Londonderry Soup"--who knows why or how? Her version, which she brought to the U.S., leaves out the egg yolks, chicken, shrimp...adds a few mushrooms, flavored with worcestershire sauce and a dot of sherry or Madeira...and serves it hot. Delicious!
Melt butter in a large saucepan over medium heat. Add onion and saute until translucent. Add curry and flour and cook at a simmer for 5 minutes. Add the stock and bring to a boil, whisking until smooth. Whip in the egg yolks and cook for a minute. Press through a fine sieve and chill. When ready to serve, stir in the cold cream and chicken or shrimp. Serve in ice-packed bowls and top with a nasturtium blossom, if available.