1. Preheat oven to 180°C/160°C fan forced. Grease a 23cm flan tin.
2. Combine biscuit crumbs and butter in a bowl, mixing well; press into the base and sides of the prepared tin. Refrigerate until firm.
3. Meanwhile, beat together NESTLÉ Sweetened Condensed Milk, egg yolks, lemon zest and lemon juice. Pour into prepared base.
4. Beat egg whites until soft peaks form; gradually beat in sugar until dissolved. Spoon meringue over filling. Bake 15-20 minutes or until golden. Serve warm or cold.