Wash the peach, skin it as desired, cut in half and remove the stone. Cut the flesh into thin slices. Peel the mango, cut the flesh as slices from the stone. Wash the carambola, dab dry and cut into slices.
Peel the grapefruit so that the white skin is completely removed. Remove the fillets with a knife between the parting skins. Collect the juice. Chop the pistachios. Mix grapefruit juice, lemon juice and vanilla sugar.
Mix fruit, pistachios and marinade. Divide into two dessert plates. Place one scoop of ice cream on each.