In a mixing bowl, combine all-purpose flour, powdered sugar, and salt. Cut in chilled butter until the mixture resembles coarse crumbs. Form the dough into a ball, then roll it out to about 1/8 inch thick. Use a round cutter to create circles for the tart pans, then prick the bases with a fork. Chill the prepared crusts for 30 minutes.

Preheat your oven to 350°F (175°C). Arrange the chilled tart crusts in your tart pans and place them on a baking sheet. Bake for 12-15 minutes or until lightly golden. Let them cool completely on a wire rack.

In a medium saucepan, whisk together fresh lemon juice, granulated sugar, eggs, lemon zest, and vanilla extract. Cook over medium heat, stirring continuously until thickened, about 8-10 minutes. Remove from heat and let it cool slightly for 10 minutes before pouring into cooled tart shells.

Carefully pour the lemon curd into the baked mini tart shells, filling them to the top. Use a spatula to smooth the surface if needed. Let the tarts sit at room temperature, then refrigerate for at least 30 minutes to allow the curd to set.

In a clean bowl, beat the egg whites with an electric mixer on medium speed until soft peaks form, about 3-4 minutes. Gradually add granulated sugar until stiff peaks form, about 4-5 minutes. If desired, fold in lilac food coloring.

Transfer the lilac meringue into a piping bag fitted with a decorative tip. Pipe the meringue in a circular motion on each tart, creating peaks.

Using a kitchen torch, toast the tops of the lilac meringue until golden brown, about 1-2 minutes. Alternatively, place the tarts under a broiler set to low for a few seconds.

For presentation, garnish with fresh mint leaves or edible flowers before serving. Arrange the tarts on a platter.