(We found the base a little too sweet - maybe use ginger biscuits or a chocolate flavour biscuit of some kind, or even leaving out the sugar in the recipe for the base. Also we all thought cream would be better than meringue!)
For the base
6oz digestive biscuits crushed
2oz castor sugar
For the filling
3 large eggs separated
2 limes finely grated zest
4.5fl oz lime juice (this needed about 7 limes in total!)
7.5 fl oz condensed milk
3 oz caster sugar
1/2 tsp vanilla extract
1/2 tsp cream of tartar
Heat the oven to 180C/350F/Gas4/Fan 160
Base: Melt butter in a saucepan then pour over the biscuit crumbs. Add the sugar and mix to combine. Spread into a 9inch pie case making sure to cover the sides well.
Filling: Whisk the egg yolks until pale and fluffy. In another bowl, whisk lime zest, juice and condensed milk until smooth and creamy. Mix into the egg yolks, and pour into pie case.
In a clean bowl, whisk egg whites until soft peaks form, and fold in the sugar, vanilla, and cream of tartar, then whisk again until stiff peaks form. Spoon the mix over the filling using a fork.
Bake in the oven for 15-20 mins or until golden brown. Remove from the oven and allow to cool. Place into the fridge to chill before serving.
Ours was kept in the fridge for a couple of days, and it was fine.