For The Nests:
4 egg whites
1/4 tsp cream of tartar
1 cup superfine sugar *see blog post for how to make at home
1/2 tsp vanilla extract
Preheat oven to 200F
Put four egg whites into the bowl of a stand mixer (or a bowl using a hand mixer)
Beat eggs at medium speed until frothy, then add in cream of tartar and continue to beat at medium speed until soft peaks form.
Add in superfine sugar a Tablespoon at a time, allowing it to gradually dissolve until all sugar is incorporated and you have stiff peaks with a glossy sheen.
Scrape down the sides of the bowl, add in the vanilla and beat another 30 seconds.
Transfer the meringue to a piping bag and pipe onto a parchment lined baking sheet. *if parchment won't lay flat, pipe a bit of meringue onto the corners and press down the parchment on top.
Pipe the meringue onto the parchment in a cup or nest form by making a circular base, then continuing the circles around the edges.
Bake the meringues in the oven at 200F for 2 to 3 hours. The exterior should be crisp, but the interior slightly soft.
Remove from oven and cool, then transfer to an airtight container until ready to serve. Can be made up to two days in advance of serving-.
For the curd
4 egg yolks
1/3 cup granulated sugar
1/4 cup lemon zest
1/2 cup lemon juice
1/2 tsp salt
8 Tbs unsalted butter, softened
Start a small pot of water over medium high heat and when steam forms, place a heatproof bowl over top of it to create a double boiler.Combine egg yolks, sugar, zest, juice and salt into the heatproof bowl, whisking constantly for 7 to 10 minutes until it thickens and creates ribbons when the whisk is pulled away from the bowl.
Remove the bowl from the heat and add in 1 Tbs of butter at a time to the lemon sauce, whisking until it melts, then add an additional tablespoon at a time in the same fashion until all are added.
If there are any visible lumps in your curd, strain it through a sieve.Then, transfer the curd to a container, placing plastic wrap directly on the top surface of the curd so that it prevents a film from forming as the curd chills.
Chill for at least three hours up to five days, then serve.