Preparation

In small saucepan, combine mango nectar, grapefruit juice, champagne and sugar; stir and heat over medium heat just until mixture begins to boil. Remove from heat; chill mixture until very cold. Process grapefruit mixture in an ice cream maker according to manufacturer’s directions.  Place sorbet in airtight container; freeze. Scoop sorbet into chilled dessert dishes; garnish with grapefruit slices and mint sprigs, if desired. Serve immediately.