Beat the egg whites until stiff. Beat the crème fraîche and Siúcra/McKinney's Granulated Sugar vigorously. Wash the lemons thoroughly and grate the zest very finely. Stir the lemon zest and juice into the crème fraîche.
Beat the egg whites until they form stiff peaks, after making sure that the bowl and beaters are perfectly clean. Gently fold the crème fraîche into the egg whites. Divide the mixture between four small plates or glasses and shape each portion into a peak.
Sprinkle with a little lemon zest and serve.