Wash 3 fruits, peel them as thinly as possible. Halve all fruits. Squeeze out the juice, place in a saucepan with sugar, star anise, cardamom and mandarin peel, bring to the boil. Boil down to a syrup in 6-8 minutes.
Pour syrup through a sieve, stir in alcohol. Pour the liqueur into one large or several small bottles and seal them.