For the curd cheese soufflé with strawberry puree, preheat the oven to 200 degrees. Whip the egg whites in a clean, chilled baking bowl until stiff peaks form. Gradually add half of the sugar and continue beating until the mixture is firm and glossy. Stir through the curd, egg yolks and lemon zest and fold in the snow. Remove the hulls from the strawberries and rinse them briefly. Butter two small ovenproof soufflé dishes and sprinkle with a tiny bit of sugar.
Fill half the amount into the molds, place a large strawberry in the center of each, and top with the remaining curd mixture. Bake on the middle rack of the heated oven for about 20 minutes until golden brown. Depending on the season, you can also add a few cherries, an apricot half or possibly a mango slice to the casserole as well.
While the casserole is baking, blend the strawberries with the remaining sugar in a hand mixer and pass the puree through a sieve.
Dust the casserole with powdered sugar and offer the strawberry puree with it. Serve the curd cheese soufflé with strawberry puree immediately warm.