The yolks of hard-boiled eggs can be worked through a sieve to mix with other ingredients, or to form a crumbly decoration called mimosa, resembling the blossoms of the mimosa tree.
Hard-boil the eggs, peel them and leave in cold water until cool. For the curry mayonnaise: fry the onion in the oil until soft but not brown. Stir in the curry powder and cook gently, stirring, for 2 minutes. Let the mixture cool, then stir into the mayonnaise. Work it through a sieve; taste for seasoning.