Preheat your oven to 200°F (93°C) and line two baking sheets with parchment paper.

In a large mixing bowl, combine egg whites, kosher salt, and cornstarch. Beat on medium speed until foamy.

Gradually add granulated sugar, continuing to beat until stiff, glossy peaks form (5-7 minutes).

Gently fold in vinegar and vanilla extract using a spatula.

Spoon dollops of meringue onto the baking sheets, creating small mounds with cavities in the centers.

Bake for about 2 hours until crisp and dry to the touch. Cool in the oven.

Prepare the lemon curd by simmering lemon juice in a saucepan until reduced by half.

In a bowl, beat butter and sugar until fluffy, then add egg yolks and whole egg with a pinch of salt.

Mix in the cooled lemon juice and ginger, then pour into a double boiler to thicken.

Stir continuously for 10-12 minutes until thickened. Strain and cool in the fridge.

Once meringues are cooled, fill cavities with lemon curd and top with berries and mint.

Dust lightly with powdered sugar before serving.