In a mixing bowl, combine all-purpose flour, powdered sugar, and salt. Cut in chilled butter until it resembles coarse crumbs. Wrap in plastic and refrigerate for 30 minutes.

Preheat oven to 350°F (175°C). Roll out the dough to about ¼ inch thick. Cut into circles and press into mini tart pans. Bake for 15-20 minutes until golden brown. Cool completely.

Whisk together eggs, granulated sugar, fresh lemon juice, lemon zest, and vanilla extract in a saucepan. Cook over medium heat, stirring until thickened, about 10-12 minutes. Cool slightly before filling tarts.

Pour lemon curd into cooled tart shells, filling to just below the rim. Smooth tops with a spatula and let sit at room temperature for 15 minutes.

Beat egg whites on medium-high until soft peaks form. Gradually add sugar, beating until stiff peaks form and glossy. Mix in lilac food coloring if desired.

Pipe the meringue over the lemon curd-filled tarts. Toast lightly under a preheated broiler for 1-2 minutes.

Optionally, garnish with fresh mint or edible flowers for elegance. Serve chilled.