Key lime pie.
For the base
175g/6oz digestive biscuits
50g/2oz Demerara sugar
And for the filling
3 large eggs
The zest of two limes finely grated
125ml/4½fl oz lime juice
210ml/7½fl oz condensed milk
80g/3oz caster sugar
½ tsp vanilla extract pinch salt
½ tsp cream of tartar
Now for this biscuit base I add Demerara sugar to the mix. It gives it something more to the texture and add a caramel flavour to the base that is just that little bit different. Just make it in the normal way make your biscuit crumbs and add the melted butter, but as it cools, other wise the sugar will melt in to the butter, add the sugar. Then pat this down in to a dish so that it makes a base for the pie, covering the bottom and the walls of the dish. Then put this to one side.
Now the rest happens fairly rapidly so preheat your oven to 180c/350f. Now get two bowls and separate your eggs, make sure that you get nothing in the egg whites as you are going to whisk them up and any egg yolk and it does not work as well.
First in another bowl whisk together the lime zest, lime juice, and condensed milk until smooth. Second, take your egg yolks and whisk them until fluffy and light, then combine the egg yolks with the condensed milk, then pour that in to the pie dish.
Now whisk your egg whites to a soft peak then fold in to that carefully the caster sugar, vanilla extract, salt and cream of tartar. Now carry on whisking till you have a very stiff peak to your egg white. Now top your pie with this meringue and with a fork shapes it in to peaks. Get the finished pie and bake for 15 to 20 minutes, or until the meringue is golden-brown.
Then remove from the oven and set to one side and let it cool. Finally place the finished pie into a fridge to chill completely letting it set fully before serving. And that is it, the only other thing to say is do not keep it to long in the fridge or the sugar starts to weep out of the meringue, and do not eat it every day as the calories in this are more than you want to think about when you actually eat it .