Adapted from Gourmet Magazine, April 2009
For the meringue:
1 cup granulated sugar
1 Tbl cornstarch
3 large egg whites (kept at room temperature for 30 minutes)
a pinch of salt
3 Tbl cold water
1 tsp distilled white vinegar
Preheat the oven to 300°F. Arrange the rack in the middle position. Draw six 3 1/4-inch circles onto a sheet of parchment paper, leaving at least 1 inch between each circle. Flip the parchment paper over and place on a baking sheet.
In a small mixing bowl, whisk together the sugar and cornstarch.
Add the egg whites and a pinch of salt to the bowl of an electric stand mixer, and using the whisk attachment, mix at medium-high speed until the egg whites become fluffy and hold soft peaks (When you stick a spoon into the cream and lift it out, a point will form then droop down after a second or two), about 2-3 minutes. Add the water and beat until the whites again hold soft peaks, about 1 minute. With the mixer running, add the sugar mixture, 1 tablespoon at a time. Once all the sugar is added, beat for 1 minute more. Add the vinegar and beat at high speed, until the mixture is glossy and holds stiff peaks (The point formed in the whipped cream will stand straight up and not fall over).
Fill a pastry bag, fitted with a 3/8-inch round tip, with the meringue. Using the circles drawn on the parchment paper as a guide, pipe a single layer of meringue in a circular motion, working from the outside in, to form a circular base. Create a border of meringue around the edge of the circle, rising about a half inch higher than the center.
Bake until the meringue is pale golden and has formed an outside crust, but is still a bit gooey on the inside, about 45 minutes. Turn the oven off and open the door slightly. Cool in the oven for 1 hour, then remove. The meringues can be stored at room temperature in an air-tight container for one day.
For the filling:
2/3 cup granulated sugar
1 Tbl cornstarch
1/8 tsp salt
1/3 cup lemon juice
1/2 stick butter
3 large egg yolks
2 tsp grated lemon zest
1/2 cup heavy cream
1 cup blueberries
1 cup blackberries
Combine the sugar, cornstarch and salt in a medium-sized sauce pot. Stir to combine. Add the lemon juice and butter and bring to a simmer over medium-high heat, whisking occasionally. Continue to simmer, whisking constantly, for 1 minute.
Lightly beat the egg yolks in a small mixing bowl. Whisk in about 1/4-cup of the lemon mixture. Then whisk the yolk mixture into the remaining lemon mixture in the saucepan. Reduce the heat to low and cook, whisking constantly, until the curd is slightly thickened. Do not let it boil. Transfer the curd to a mixing bowl and stir in the lemon zest. Chill in the refrigerator, stirring occasionally, until cool, about 2 hours.
Beat the cream until it holds stiff peaks. Fold the whipped cream into the lemon curd.
Fill each meringue cup with the lemon curd mixture. Arrange a mound of blueberries and blackberries on top. Serve immediately.
SERVED AT THIS DINNER PARTY