Preheat to 350°F (180°C) and grease an 8-inch (20cm) fluted loose-base quiche pan.

Crush the biscuits into fine crumbs and mix with melted butter. Press into the pan. Bake for 8 minutes and cool.

Mix condensed milk, lemon juice, zest, and egg yolks. Pour into the baked crust.

Bake for 22-25 minutes until the filling is just set with a slight jiggle.

Beat egg whites until stiff. Gradually add sugar until glossy. Spoon onto the filling and create peaks.

Bake for another 12 minutes until meringue is golden.

Cool and set for about 3 hours. Cut into generous slices and enjoy!