Meringue Cups with Lime Cream and Fresh Berries

Position a rack in the center of the oven and preheat the oven to 225°F (107°C). Trace six 3 1/2-inch circles onto a sheet of parchment paper. Turn the parchment paper upside down and place it on the baking sheet.

In the bowl of an electric mixer, using the whisk attachment, beat the egg whites at medium speed until foamy. Add the salt and cream of tartar and beat at medium-high speed until soft peaks begin to form. Gradually add the sugar, about 1 tablespoon at a time, then increase the speed to high and beat the whites until stiff peaks form.

Scrape the meringue into a large (18-inch) pastry bag fitted with a medium plain tip (such as Ateco #4). Starting in the center of each circle, pipe a spiral of meringue out toward the edge, filling the circle completely. Pipe a ring of meringue around the edge of each circle. Pipe another ring of meringue on top of the first, to form cups.

Bake the meringues for 2 hours, or until they are very lightly colored and dry to the touch. Let them cool completely.

Set a fine-mesh sieve over a medium bowl and set aside. In a medium, heavy non-reactive saucepan, whisk together the egg yolks and sugar until blended. Stir in the lime juice and butter, and cook over medium heat, whisking constantly, until the mixture turns opaque and thickens enough to leave a path on the back of a wooden spoon when you draw your finger across it. Remove the pan from the heat and immediately strain the custard through the sieve, pressing it through with a rubber spatula. Stir in the lime zest. Set the mixture aside while you whip the cream. Or, if you are not ready to serve the meringues, refrigerate the mixture, covered, until ready to use.

Shortly before serving, in the bowl of an electric mixer, using the whisk attachment, beat the heavy cream at high speed until medium-firm peaks form. Place the bowl of whipped cream in the refrigerator.

If the lime mixture has not been refrigerated, set the bowl containing the lime mixture in a large bowl filled about one-third of the way with ice water (be careful that the water doesn’t splash into the lime mixture). Stir the mixture frequently until it is slightly cooler than room temperature, about 10 minutes.

Fold a large spoonful of the whipped cream into the lime base to lighten it. Gently fold in the remaining cream.

Spoon the lime cream into the meringue cups, dividing it evenly. Top each meringue with mixed berries, then dust lightly with confectioners’ sugar and serve. Store the unfilled meringue shells in an airtight container in a cool, dry place for up to 5 days; once filled, they should be served immediately.