Preheat oven to 170°C. Line base of a 20cm springform tin with baking paper.

Process biscuits until fine crumbs. Add almonds and melted butter, process until combined. Press mixture firmly into the base and 3cm up sides of tin. Refrigerate.

Separate egg yolks, and whisk with sweetened condensed milk. Stir in lime juice and the lime rind. Pour into biscuit base and bake for 5 minutes.

Whisk egg whites until soft peaks form. Sprinkle in sugar and whisk until peaks are glossy. Pipe onto into milky mixture.

Bake for 40-45 mins or until set. Cool. Serve with extra lime slices.