Preheat the oven to 200 degrees F. Line 2 baking sheets with parchment paper. Using a small glass and a pencil, draw 6 (3 1/2-inch) circles on each piece of paper. Turn the paper face-down on the baking sheets.
In the bowl of an electric mixer fitted with the whisk attachment, beat the egg whites, cream of tartar, and a large pinch of salt on medium speed until frothy. Add 1 cup of the sugar and raise the speed to high until the egg whites form very stiff peaks. Whisk in the vanilla. Carefully fold the remaining 1/2 cup of sugar into the meringue. With a large star - shaped pastry tip, pipe a disc of meringue inside each circle. Pipe another layer around the edge to form the sides of the shells.
Bake for 2 hours, or until the meringues are dry and crisp but not browned. Turn off the heat and allow the meringues to sit in the oven for 4 hours or overnight.
Spread some of the sauce from the stewed berries on each plate. Place a meringue on top and fill with whipped cream. Top with berries and serve.
