- Place the watermelon puree and lime juice into a small heavy bottom sauce pot and bring to a simmer. While the liquid is heating, place the egg yolks into a medium size mixing bowl. Combine the sugar and the cornstarch, then whisk the mixture into the egg yolks. Temper the simmering liquid into the egg yolk and cornstarch mixture. Return the mixture back to the sauce pot and cook over medium low heat while whisking constantly until you see one or two bubbles form. Strain immediately into a clean bowl. Whisk in the butter one piece at a time until all of the butter is incorporated. Cool completely and transfer to an airtight plastic container and store up to 5 days in the refrigerator.
- 2. To prepare the salt crust, combine the cold butter, salt and flour into a mixer fitted with the paddle attachment. Run on low speed until the butter is pea sized. Add ice cold water all at once and mix gently until the dough is just combined. Transfer to a floured surface and roll the dough out as thin as possible (about the size of a half sheet pan and keeping a rectangular shape). Place the dough onto the backside of a sheet pan and wrap in plastic wrap. Refrigerate the dough for at least 2 hours, preferably overnight. Once the dough has been chilled thoroughly and set, continue to roll this out on a floured work surface to approximately 12x24 inches. Cut into 24 rectangles 3x4 inches each. Place 2 tbsp. of the watermelon curd into the very center of the raw pastry rectangle. Brush the edges with some of the reserved egg whites and top with an additional square. Use a fork to crimp the sides and seal in the filling. Repeat for the remaining tarts and bake in a 350 oven for 30 min. Allow them to cool completely before glazing and garnishing with chocolate chips.
- 3. To make the glaze, whisk the powdered sugar, milk, and food coloring in a bowl until mixture is smooth. If the mixture seems too thick, add more milk 1 teaspoon at a time. Drizzle the glaze over the cooled tarts and garnish with the chocolate chips. Serve at room temperature.