Place biscuits in a plastic bag and crush with a rolling pin or a small glass.
Mix biscuit crumbs with lemon rind in a mixing bowl and add water and margarine. Stir to bind it together.
Press onto the base and sides of a 22cm pie dish and place in the fridge until needed.
Mix condensed milk and lemon juice in a mixing bowl until thickened and stir in the cottage cheese.
Pour filling over the biscuit base and refrigerate for 2 hours or overnight.
Serve with any fresh fruit.
Stir 1 x 115 g tin granadilla pulp into the filling for a different flavour.