Whisk the milk, sugar, lime juice and butter in a medium saucepan over medium heat. Add the egg yolks and whisk constantly until the curd thickens, 8 to 10 minutes. Strain the curd through a fine-mesh strainer into a medium bowl and cool in the fridge or over an ice bath. Fold the curd into the mascarpone, and add the coconut and lime zest.
Take a Giant Macaron and spread with a generous tablespoon of the mascarpone filling. Top off with another macaron and dig in.
Preheat the oven to 300 degrees F. Combine 100 grams of egg whites with the tant pour tant and add desired color or flavoring and reserve. Boil the sucrose with the water to soft ball stage, or 240 degrees F. Add the sucrose mixture to the dried egg whites and the remaining 110 grams of egg whites to a stand mixer with a whisk attachment and whip until stiff peaks. Fold the tant pour tant mixture into the whipped meringue. Pipe in a bag to desired diameter, and let dry at room temperature for 20 to 30 minutes. Bake for 10 to 20 minutes depending on size. Yield: 12 to 16 macarons.
Recipe courtesy Chef Andy Schneider at Le Reve Cafe and Patisserie
You can also use vanilla wafers, such as Nilla wafers, instead of the macarons.