Briefly wash the strawberries under cold water, remove the stems, halve or quarter the strawberries depending on the size.
Peel the pineapple, cut out the brown indentations with a sharp knife. Dice the lower 2/3 of the pineapple. Mix the pineapple and strawberries with sugar and let it steep for a few hours. Pour white wine 1/2 hour before serving, add sparkling wine immediately before serving. Place the top 1/3 of the pineapple in the punch bowl as a garnish.