Carefully wash the ripe apricots. Cut them in half and remove the stone, then put the fruit through a food mill or potato masher into a bowl, add the grated ginger, dilute with a little water and stir. Taste the mixture and if you don’t think it’s sweet enough, add a little sugar. Stir again, cover the bowl with cling film and put it in the fridge for at least 30 minutes. Then pour the apricot and ginger mixture into a jug, give it another good stir and – tilting the jug slightly – slowly pour in the sparkling wine. Mix delicately and serve chilled.