Custard tart

Custard tarts or flan pâtissier/parisien are a baked pastry consisting of an outer pastry crust filled with egg custard. The development of custard is so intimately connected with the custard tart or pie that the word itself comes from Anglo-Norman *crustade , meaning a kind of pie. It is derived from Anglo-Norman crust (> English crust) corresponding to French croust. It is related to the 18th century French term croustade, probably borrowed from the Italian crostata (already mentioned 13th century), derived from crosta (croûte in French), more probably than the Occitan Occitan: croustado, lit. 'tart'. Some other names for varieties of custard tarts in the Middle Ages were doucettes and darioles. In 1399, the coronation banquet prepared for Henry IV included "doucettys".

Source: Wikipedia