Instructions:

1. Preheat oven to 300ºF with rack in the middle.
2. Trace an approximately 7-inch circle on a sheet of parchment paper.
3. Turn parchment paper over and put on a baking sheet.
4. Whisk together in a small bowl:
• 1 cup granulated sugar
• 1 TBS cornstarch
5. In a separate bowl, using a handheld mixer at medium speed beat until they hold soft peaks:
• 3 egg whites , at room temperature 30 mins
• ¹/₈ tsp salt
6. Increase speed to medium-high and whip in sugar mixture 1 TBS at a time.
7. After all sugar has been added, beat 1 minute more.
8. Mix in:
• 1 tsp white vinegar
9. Beat at high speed until meringue is glossy and holds stiff peaks, about 5 minutes (longer if using handheld mixer).
10. Gently spread meringue inside circle on parchment, making edge of meringue slightly higher than center (the "crater" is for curd and fruit).
11. Bake until meringue is pale golden and has a crust, about 45 minutes (inside will still be marshmallow-like).
12. Turn oven off and prop door open slightly with a wooden spoon.
13. Cool meringue in oven 1 hour.
14. Make lemon curd while meringue bakes.
15. in a 2-quart heavy saucepan over medium high heat, stir together:
• ²/₃ cup granulated sugar
• 1 TBS cornstarch
• ¹/₈ tsp salt
• ¹/₃ cup lemon juice
• ¹/₄ cup butter, unsalted
16. Keep whisking until well blended, then continue to simmer, whisking constantly, 1 more minute.
17. In a small bowl, lightly beat:
• 3 egg yolks
18. Whisk in 1/4 cup lemon mixture, then whisk into remaining lemon mixture in saucepan.
19. Reduce heat to low and cook, whisking constantly, until curd is thickened, about 2 minutes (do not let boil).
20. Transfer to a bowl and stir in:
• 2 tsp lemon zest , grated
21. Cover surface with parchment paper, and chill in the refrigerator until cool, about 1 1/2 hours.
22. When ready to serve, pour in a chilled bowl:
• 1 cup heavy cream
23. Using a handheld mixer, beat cream until it just holds stiff peaks, then fold 1/4 cup beaten cream into curd to lighten.
24. Spoon lemon curd into meringue and mound berries on top.
25. Serve remaining whipped cream on the side.