In a blender or food processor, puree the strawberries. Strain through a fine mesh strainer into a tall pitcher, pressing with the back of a spoon to extract the juice. Add the papaya juice, Grand Marnier, and sugar, and stir to dissolve the sugar. Refrigerate until well chilled. Add the sparkling wine to the pitcher and stir gently to mix. Pour into tall Champagne glasses and garnish each glass with a strawberry half. Serve immediately.
Yield: 8 servings