At least 3 hours before serving, whip the cold single cream to stiff peaks. Whip the egg whites until stiff, then gently fold the two mixtures together, whisking for just 10 seconds.
Line 4 small heart-shaped cheese strainers (with draining holes) with muslin cloth—each holding about a quarter of the preparation. Fill them, fold the corners of the muslin over the top, and refrigerate for at least 3 hours.
When ready to serve, hull, wash, and drain the fruit.
Mix the heavy cream and milk in a bowl without whisking, just to lighten it. Remove the strainers from the refrigerator, unfold the muslin corners, and invert the hearts onto dessert plates.
Remove the strainers and muslin. Surround the hearts with fresh fruit, top each with a spoonful of the lightened cream. Serve the remaining cream in a sauce boat alongside the powdered sugar and cream hearts.
Source: C.I.D.I.L
