Lemon-Lime Tart

Combine the flour, powdered sugar, butter, and egg to form a dough, then chill for 1 hour.

Roll out the dough, fit it into a tart pan, and dock with a fork. Blind bake with weights at 180°C (350°F) for 15 minutes, then remove the weights and bake for another 10 minutes. Let cool.

Zest and juice the lemons and limes.

Whisk the eggs, sugar, citrus juice, and zest together, and cook over a double boiler until thickened.

Remove from heat, whisk in the butter until smooth, and strain. Let cool slightly.

Pour into the prepared crust and chill for at least 4 hours.

For the meringue, whip the egg whites and sugar over a double boiler, then beat with an electric mixer until stiff peaks form, adding a splash of lemon juice.

Spread the meringue over the tart and brown with a kitchen torch or under the broiler at 220°C (425°F) for 2–3 minutes.