Position an oven rack in the center of the oven and preheat to 170 degrees F (80 degrees C). Line a baking sheet with parchment paper. For the meringues: Beat the egg whites with an electric mixer fitted with the whisk attachment on medium-high speed until they hold soft peaks. Start adding the sugar, 1 tablespoon at a time, and continue to beat until the meringue holds very stiff peaks. Test to see if the sugar is fully dissolved by rubbing a little of the meringue between your thumb and index finger. The meringue should feel smooth, not gritty. If it feels gritty the sugar has not fully dissolved, so keep beating until it feels smooth between your fingers. Gently spread the meringue into 8 small rounds on the parchment paper, smoothing the edges and making sure the edges are slightly higher than the center. (You want a slight well in the center of the meringues to place the cream and compote.) Bake until the outside of the meringues is dry, about 3 hours. (The outside of the meringue will feel firm to the touch if gently pressed, but as it cools you will get a little cracking and it will have a marshmallow texture.) Let cool. For the ground cherry compote: Combine the cherries, sugar, and citrus zests and juice in a saucepan. Simmer until the cherries are translucent and the liquid is syrupy, about 25 minutes. Transfer to a bowl and let cool. For the white chocolate cream: Bring the cream just to a simmer in a saucepan. Whisk together the egg yolks and sugar in a bowl. Slowly pour in the hot cream, whisking constantly, than return the mixture to the saucepan. Cook over medium heat until thickened, about 2 minutes, stirring constantly. Put the chopped chocolate in a large bowl. Pour the hot cream mixture through a strainer over the chocolate. Stir until the chocolate is melted. Refrigerate for 1 hour. Beat the white chocolate mixture with a mixer until pale and thick. To serve, place each meringue on a serving plate. Fill the centers with a dollop of white chocolate cream and top with the cherry compote.
The cooled meringues can be stored in an airtight container in a cool, dry place for a few days. The cherry compote can be served on pancakes, waffles, or ice cream. The white chocolate cream can also be used to frost a cake.