Pomegranate and Orange Champagne Punch

pomegranate seeds, separated

mint leaves

pomegranate juice

orange juice

orange-flavored liqueur, such as Grand Marnier

bottles (750 ml) Champagne, Prosecco or other sparkling white wine

orange, sliced

**To make this non-alcoholic, substitute the champagne with 1 liter orange flavor sparkling soda and omit the orange-flavor liqueur.