2. In a food processor, blitz the biscuits so that they resemble a breadcrumb texture. Pop these into a bowl.
3. In a small pan, melt the butter and add it to the biscuits and mix through.
4. Pop the mixture into a 22 cm tart tin, and press it down so that it’s an even thickness across the tin and up the sides. Leave aside to cool.
5. In a bowl, pop in the egg yolks and whisk for about 1 minute using an electric whisk. Add in the condensed milk and whisk through for another couple of minutes. 6. Now mix in the juice and zest of the limes, and pour the mixture into your pie base.
7. Pop back into the oven for about 15 minutes. After this, remove from the oven and chill for at least 3–4 hours, but if you can do it overnight, all the better!
8. To serve, carefully take the pie out of the tin and slice a generous piece onto a plate. Add the cream to the icing sugar and whisk until you have soft peaks. You can serve this cream either spread on the cake or dolloped on each individual slice.
9. Finish the dish off by sprinkling some lime zest over the pie, and grate some of the dark chocolate on there too!