1.Shell eggs and cut off tops at one end,just enough to uncover yolks.
2.Scoop out yolks with a small spoon taking care not to break whites.
3.Mash yolks.Cream butter and add mashed yolks.
4.Bone sardines.Pass through a sieve.Add to egg mixture.Season to taste and cream well.
5.Stuff eggs with mixture.
6.Trim bread.Spread with remaining mixture and place eggs cut side dwon on bread.
7.Decorate with slices of gherkins.