In a food processor or blender, combine the strawberries and sugar and purée until smooth. Transfer the mixture to a fine-mesh sieve set over a bowl. Press with a rubber spatula to force the pulp through while leaving the seeds behind. Stir in the kirsch. Cover and refrigerate until thoroughly chilled. Freeze in an ice-cream machine according to the manufacturer’s directions. Transfer to an airtight container and store in the freezer until serving.
About 15 minutes before serving, sweeten the sliced berries to taste with superfine sugar. Toss gently and let stand to release some of the berry juices. Stir in kirsch to taste.
FOR SERVING
Scoop the sorbet into stemmed glasses or dishes. Spoon the berries over the sorbet, dividing them evenly. Pour 2 tablespoons of the sparkling wine over each portion and serve immediately.
Notes
Your guests are sure to enjoy every bite - and every sip!