Heat the butter in a wide-bottomed pan, sauté the onions, garlic, pumpkin and sage for a few minutes. Pour in the wine and stock, bring to the boil, boil off all of the liquid, season. Place in a bowl and allow to cool slightly. Mix in the feta.
Grease the moulds with butter.
Fold the strudel pastry sheets over one another, glaze with a little butter, place on a piece of kitchen towel, cut into 6 squares, and place in the prepared moulds. Place the filling into the moulds, fold the excess pastry loosely over the top, and close the pies. Glaze the surface with the rest of the butter, and scatter poppy seeds over the top.
Bake: for 20-25 mins. in the centre of an oven preheated to 200°C.