Make the crust: Mix all the crust ingredients except the water. Add water gradually just until the dough comes together. Press the dough into a 22-centimeter (9-inch) tart pan — no need to grease it. Chill for at least 30 minutes, or overnight.
60 grams sugar, 100 grams unsalted butter, 3 egg yolks, 200 grams all-purpose flour, 1/4 teaspoon salt, 1 teaspoon water
Bake the crust: Prick the base with a fork and bake at 350°F (180°C) for around 30 minutes or until golden brown. Cool to room temperature.
Make the filling: In a bowl, combine the condensed milk, lemon juice, lemon zest, and cream. Mix well. Taste and adjust lemon juice as needed. Pour into the cooled crust.
2 cans sweetened condensed milk, Juice of 4 to 7 lemons, Zest of 1 lemon, 200 milliliters whipping cream
Make the Swiss meringue: Set a heatproof bowl over a pot of simmering water. Add egg whites and sugar. Whisk constantly for 4 minutes, until the mixture is warm and sugar has dissolved (rub between your fingers to check).
3 egg whites, 200 grams sugar
Transfer to a mixer and beat on high for about 10 minutes, until stiff, glossy peaks form and the meringue has cooled.
Assemble: Spread the filling over the crust. Top with big swoops of meringue. Use a torch to brown the top, or leave it soft and white if you prefer.
Chill until ready to serve.