Put the crushed biscuits in a bowl .

Add the zest and f half a lemon

Pour over the melted butter

Mix well

Then put into the bottom of springform or loose bottomed tin

Put the mascarpone, lemon curd, and lemon juice in a bowl and mix until smooth

Spoon on top of the biscuit base and level the top.

Chill in the fridge for at least 4 hours to firm

Decorate with the thinly sliced lemon slices and icing sugar