From How to be a Domestic Goddess by Nigella Lawson.
A lot of people, including me, really love limes, which is why the rumoured limepocalypse (limegeddon, limetrastrophe) is so terrifying. So let’s make the most of them while we still can. My wonderful friend T.O.M loves limes more than anyone else I know, and I made this dessert as a contribution to her hen party a few weeks ago. T.O.M may now love Steven (who takes brilliant photos) a little bit more than limes, but there is probably not much in it.
This is the second key lime pie recipe in How to be a Domestic Goddess, and I have made both of them. They are both really tasty, but this one wins by being so easy to make. No egg-separating, no baking, just mix and set. The only complication I had was that the bowl of the mixer was a bit too full, and little bits of limey cream splashed my hair, clothes, the kettle, and the boxes of different kinds of tea. It must have been a suitable libation sacrifice to the lime gods, because it made one of the nicest desserts I have ever made – creamy, rich and light at the same time, and absolutely delicious.
You will need a 23cm springform or loose-bottomed tin (I used the wrong size tin and messed up the quantities a bit, which is why my key lime pie looks a bit heavy on the base, but if you follow these quantities it should turn out perfectly)
For the base:
200g digestive biscuits, smashed to crumbs (ginger or coconut biscuits might make an interesting variation)
50g softened butter
For the filling:
Juice and zest of 4 limes
397g can of condensed milk
300ml double cream
To make the base, melt the butter and mix it with the biscuit crumbs. Press the buttery crumbs into the cake tin and leave it to set in the fridge for at least half an hour.
To make the filling, simply mix all the ingredients together, and whisk until it has thickened a bit. This is easier to do using an electric hand-held whisk or free-standing mixer. Pour the thickened mixture into the buttery biscuit base, and let it set in the fridge for a few hours (at least) before serving.