Preheat oven to 250 degrees Fahrenheit. Cover two baking sheets with parchment paper. Draw four four-inch circles on each piece of paper. Turn paper over. (You should be able to see the markings through the paper.)

Place salt and four egg whites in a large bowl; beat with a mixer at high speed until foamy. Gradually add 3/4 cup granulated sugar, one tablespoon at a time, beating until stiff peaks form.

Divide the egg white mixture evenly among the drawn circles. Shape meringues into nests with one-inch sides using the back of a spoon. Sprinkle evenly with nuts.

Bake at 250 degrees Fahrenheit for one hour. Turn oven off, and cool meringue nests in the closed oven for two hours. Remove from oven, and carefully remove meringue nests from paper.

Combine whole eggs and one egg white in a medium bowl; stir well with a whisk.

Heat sugar, juice, potato starch, and salt over medium-high heat in a small saucepan until tiny bubbles form around edge. Gradually add hot juice mixture to egg mixture, stirring constantly with a whisk. Return juice mixture to pan.

Cook over medium heat for two minutes or until thick, stirring constantly.

Spoon curd into a bowl; cool to room temperature. Cover and chill.

Arrange about 1/4 cup fruits in each meringue nest; top with about two tablespoons lemon curd. Serve immediately.