I enjoy a tart dessert, and with that in mind, this is my version of a lemon meringue pie. It combines a lemon-lime custard filling with an Italian meringue. Use your own favorite pie crust here; I use the almond vanilla crust described here:
Whisk together the dry ingredients in a medium saucepan. Add the water, lemon juice, and lime juice, and bring to a boil over medium-high heat: Cook for 75 seconds, or until the filling is very thick, and clear. Reduce heat to low.
Combine 1/4 cup of the custard base with the egg yolks, then mix the yolk into the saucepan. Cook over low heat for 1 minute, whisking constantly, and without boiling the custard. Remove from heat, and whisk in the zest and butter.
Fill your pie shell with the custard, place a piece of parchment paper, or plastic wrap over the top, and let rest in the fridge 1 hour, or until the custard is completely cool.
Mix the sugar and water in a small saucepan until no lumps remain, and cook until the syrup reaches 240 F (soft ball).
While the syrup cooks, beat the egg whites into soft peaks. Add the citrus juice and salt, and beat the whites into stiff peaks.
When the syrup is ready, transfer it to a heat-safe measuring cup to arrest the cooking process. While beating the whites on low speed, gradually drizzle the syrup into the whites, avoiding drizzling the syrup directly onto the beater.
Continue beating the meringue on medium speed until fluffy, and completely cool.
Remove the paper or plastic from the top of the custard, spoon dollops of meringue in a ring around the edge of the crust, and pile the remainder in the center. Shape the meringue into a mound, and decorate it.
Blowtorch the meringue to caramelize the surface, or briefly place it under the broiler, up to a minute.