Photo: Jonathan Buckley
Put the rhubarb in a large pan and add 1½ litres cold water. Peel 4 strips of orange skin from each orange and add to the pan with the juice from both oranges and the star anise.
Bring the rhubarb to the boil, then turn down the heat and simmer gently until soft. Allow to cool for 1 hour.
Pour the rhubarb and juice into a large jelly bag hanging over a large bowl and allow the juice to drip through overnight. Pour the strained juice into a pan and add the sugar. Stir over a low heat until dissolved.
Allow the cordial to cool. Store in the fridge and dilute to taste.