Last night I baked a conrflour quiche
Would like to hear more about that. Do you mean you used cornflour for the pastry?
You asked about putting oil in the filling. Well I've not come across that other than the fat contained in milk or cream - the classic filling is eggs and cream or milk. Maybe because you didn't include dairy it was missing that fat?
Mod.comment: I'm copying your post and my reply to the 'Dish of the month' thread.