To make a pastie:

Take some pastry: flaky pastry, filo pastry and puff pastry will work ok. Roll it out thin, and cut it into circles with a diameter of around 20 - 30 cm.

Prepare your filling. This can be anything from cooked vegetables which are cut up small, to cheese and bacon .

Place filling on one half of each circle, leaving a bit of room around the edge. Beat an egg, and brush exposed edges with egg (using it like glue). Fold the pastry in half over the filling. Press the edges down with a fork to seal them. The pastie should look like a bulky semi-circle. Brush last of egg lightly over top of pastie, and bake it in the oven until the pastry is brown.