Preheat oven to 200°F (95°C). Line a large baking sheet with parchment paper.
Whisk egg whites with an electric mixer on high until foamy. Gradually add sugar, mixing constantly on medium. Increase speed to high and whisk until egg mixture holds stiff peaks, about 7 minutes. Whisk in vanilla.
Spoon meringue into 6 portions on prepared baking sheet. Use a spoon to shape a “nest” in the centre of each one.
Bake for about 1½ hours or until dry. Let cool on a rack.
Lemon Curd and Mixed Citrus
Combine lemon juice and zest, sugar, eggs and egg yolks in a medium pot. Whisk well and whisk in butter. Heat over medium-low, alternating between a whisk and a heatproof spatula, until thickened and just starting to bubble, about 6 minutes.
Transfer lemon curd to a bowl and cover surface. Chill until cold, about 1 hour.
To assemble, place a meringue nest on each plate and fill with lemon curd. Cut off peels from grapefruits and oranges. Slice thinly and serve alongside meringue nests.
Nutrients per serving: 268 calories, 4 g protein, 9 g fat (4 g saturated fat), 46 g carbohydrates, 0 g fibre, 142 mg cholesterol, 98 mg sodium.
Tip: To make lemon curd extra-smooth, pour it through a fine mesh sieve before chilling.