How to Make It
Preheat oven to 300˚F. Line a baking sheet with parchment paper.
In the bowl of a stand mixer fitted with the whisk attachment, beat the egg whites and salt together on medium until soft peaks form. Increase the mixer to high speed and gradually add the sugar, one tablespoon at a time, beating well after each addition. Continue beating until the meringue is thick and glossy and holds stiff peaks. Add the vanilla and vinegar and cornstarch, and beat for 2 or 3 seconds more, just to combine.
Scrape the meringue onto the lined baking sheet and use an offset spatula to spread it roughly into a 9-or-10-inch round. Immediately place on the middle rack of the oven and reduce the heat to 250˚. Bake for 1 1/2 hours until the meringue is crisp and dry to the touch and still very white. Turn the oven off and prop the door open with a wooden spoon. Cool completely in the oven. Transfer the meringue shell to an airtight container until ready to serve.
While the meringue is baking, make the filling. In a medium bowl, stir together the sweetened condensed milk and the lime juice. Cover the bowl with plastic wrap and refrigerate for at least an hour. Use an electric mixer and beat the cream to firm peaks. Fold the cream into the lime filling. Cover and refrigerate until ready to serve. The cream will thicken more as it chills.
Right before serving, wash and dry the strawberries, removing the green tops and slicing most of them in half, but leaving some of the smaller berries whole. Toss with 2 or 3 tablespoons of sugar and let macerate until the sugar dissolves and forms a light syrup from the berries' juices.
Place the meringue on a serving plate or cake stand and dust lightly with confectioners’ sugar. Fill with lime cream. Top the lime cream with berries and drizzle with berry juices if desired. Serve immediately.