Wash organic orange hot, dry, cut in half and cut 4 thin orange wedges from one half. Squeeze the other half and the remaining orange (there should be approx. 1⁄8 l juice). Mix juice, Lillet and Grand Marnier.
Half fill glasses with ice cubes. Spread the juice-lilytte-mix into the glasses. Add 1 orange wedge each and fill up with crémant. Serve with straw.