Piece of Zesty Citrus Tart

Heat the oven to 160°C (140° fan) 325°F gas 3. Grease a loose-based 23cm|9" flan tin.

For the base: crush the biscuits to crumbs in a food processor or in a plastic bag with a rolling pin. Mix together the crumbs, butter and sugar and press into the base and sides of the tin.

Bake for 10 minutes, then remove from the oven and set aside to cool.

For the filling: whisk the egg yolks in a mixing bowl with an electric whisk until combined. Whisk in the condensed milk until smooth, then whisk in the lime zest and juice.

Pour the mixture into the pie case. Bake for 15 minutes. Cool completely in the tin, then chill for at least 3 hours before removing from the tin.

For the topping: whisk the cream and icing sugar until thick. Spoon on top of the filling and spread evenly, forming peaks around the edge of the pie.