Mentchikoffs look a bit like white broad beans. They have a praline chocolate centre, covered with a crunchy white shell of Swiss meringue (made with egg whites and icing sugar).
They were invented in 1893 during the Franco-Russian alliance, back when everything Russian was in fashion. Someone even came up with a Crème Francorusse (instant chocolate pudding powder) which was sold into the early 1970s.
Meanwhile a confiseur named Daumesnil in Chartres gave his new bonbons a Russian name as well, choosing Prince Alexandre Danilovitch Mentchikoff (1672-1729), the favourite of Peter the Great—and who was said to be the son of a pastry chef.
Image by ville de chartres