On a clean surface, using a rolling pin, flatten one ball to a flat sheet, a little larger than the baking pan, and not very thin.
Put the sheet on the greased pan, and tuck it in to fill the corners. Leave the edges to overflow. If the dough tears, use a small piece of dough cut from the edge, to close the gap.
Cover the dough with the filling.
Spread small pieces of margarine on top.
1 tbsp Margarine (unsalted)
Flatten the second ball of dough to a flat sheet, a little larger than the baking pan. Cover the filling.
Leaving a bit of the edge to fold in and seal the pie, cut off the leftovers all around the pan.
Lift the edges of the bottom sheet of dough, and fold them above the top layer, tighten the layers together.
With a sharp knife, cut three cuts in the top layer to allow steams to come out during the baking.
In an over warm to 350f (180c), bake for 50 minutes until golden brown.
Leave to cool a little before serving as the filling may be extremely hot.