Preheat the oven to 425 deg F (220 deg C)
Grease a loose bottom 9 inch (23cm) pie pan that is at least 2 inches (5cm) deep.
Line the pie dish with pastry (homemade or shop bought) and trim the edges.
Prick the crust repeatedly with the tines of a fork then cover the pastry with baking parchment and add ceramic baking beans or dried beans.
Bake blind until the edges begin to brown (about 10 minutes) before removing the parchment lining and brushing the pastry with lightly beaten egg white, baking for a further 5 minutes.
Remove from the oven and set aside.
Reduce the oven heat to 375 def F (190 deg C).
Whisk together the pumpkin puree, eggs and sugar then add the rest of the ingredients, stirring well. This mixture will be quite thick.
Pour into the pie crust and bake for around 35 - 40 minutes until the filling is just set. It should still have a slight wobble when you remove it from the oven.
While the pie is cooking make the meringue. Whisk the egg whites until they form stiff peaks in a large bowl then beat in one tablespoon of the sugar at a time until it is all incorporated and the mixture is thick and glossy.
Spoon the meringue on top of the pie and take it to the edge of the pastry rim with a palette knife ensuring it seals the edge completely. Make a few swirls on top and place it back into the oven for about 15 to 20 minutes. Leave to cool completely before removing from the tin.
Serve with a light dusting of icing sugar.