Boil eighteen eggs hard, separate the whites from the yolks after removing the shells. Chop the whites small, and rub the yolks of six of the eggs through a fine hair-sieve. Put two onions, cut into small pieces, in a fryingpan with four ounces of butter, and fry but not brown; then add one tablespoonful of flour and mix thoroughly, pour in sufficient boiling milk to just moisten the whole, and season with a little'salt and pepper. When the sauce is ready, put in the six yolks and the whites, stir well, and let the mixture cool. Form it into croquettes, spread these over with breadcrumbs, fry them in boiling fat to a light brown, and serve. The remainder of the yolks can be used for other purposes.