Roll out a sheet of ready-made puff pastry and cut it in half. Place one half on a baking tray lined with parchment paper.

In a heavy-bottomed pan, gently sauté the leek (sliced into rings) in a bit of vegetable oil until soft. Add salt and spices, then let it cool.

Mix the cooled leek with the grated cheeses and spread the filling over the pastry sheet on the tray. Cover with the second half of the pastry and seal the edges well. Prick the top with a fork in several places to allow steam to escape.

Preheat the oven to 180°C (fan setting) and bake the pie for 25–30 minutes until golden brown.

Serve warm with a green salad.