Is a flan classified as pastry or does it just contain pastry? I've searched online without fruition.
A flan, in English and other cuisines, is a dish with an open, rimmed pastry or sponge base containing a sweet or savoury filling. Examples are the quiche lorraine, custard tart, leche flan, and the South African melktert.
The Merriam-Webster definition of pastry is
a dough that is used to make pies and other baked goods and typically has a high fat content
So you can say that the flan is a pastry, since it has a pastry base.
Now if you're thinking flan as the spanish version (Crème caramel) then it's not a pastry, it's a custard.
A Latino flan is just a custard. A French flan is a slightly thicker custard in a pie crust. So neither ever contains pastry :-). Custard doesn't qualify as pastry, which always involves some sort of dough.