Melt the butter and sugar in a pan.
Remove from the heat. Stir in the peel and fruit. Roll out the pastry
on a lightly floured surface and use to line a 23 cm/9 in pie plate.
Beat the eggs with the whisky, if using, and stir into the fruit
mixture. Turn into the pastry-lined plate. Bake in a preheated oven at
220°C/425°F/gas mark 7 for 20 minutes. Reduce the heat to
180°C/350°F/gas mark 4 and continue cooking for a further 15 minutes
or until puffy and golden and the filling is set. Serve warm with
Atholl Brose Cream.