"I like unsweetened whipped cream on top," van Boven says, "because the fruit is sweet enough on its own."
Ingredients
3 large egg whites
1/2 teaspoon cornstarch
1/8 teaspoon cream of tartar
1/2 cup plus 1/3 cup sugar
1 teaspoon fennel seeds, lightly crushed
12 ounces fresh strawberries, hulled, halved or quartered if large (about 3 cups)
6 ounces fresh raspberries (about 2 cups)
1 teaspoon finely grated lemon zest
1 tablespoon fresh lemon juice
3/4 cup chilled heavy cream
3/4 cup mascarpone
2 tablespoons fresh tarragon leaves
Directions
Preheat oven to 200°. Using an electric mixer, beat egg whites, cornstarch, and cream of tartar in a large bowl until frothy. Gradually beat in 1/2 cup sugar, 1 tablespoonful at a time, until stiff peaks form. Beat in fennel seeds.
Spread out meringue on a parchment-lined baking sheet into an 8" round about 3/4" thick in the center and 1 1/2" thick at the edges, creating a well for the filling.
Bake meringue until firm to the touch, about 3 hours. Turn off oven and let meringue cool in oven, about 2 hours.
About 30 minutes before serving, toss strawberries, raspberries, lemon zest and juice, and remaining 1/3 cup sugar in a large bowl; let stand to let fruit release juices.
Meanwhile, using an electric mixer, beat cream until soft peaks form. Beat in mascarpone just to blend.
Carefully transfer meringue to a serving platter. Fill with whipped cream mixture. Top with berry mixture and tarragon.
DO AHEAD: Meringue can be made 1 day ahead. Store airtight in a cool, dry place.
