- To remove the bitterness from the mandarin peel, place the whole, unpeeled mandarins into a pot and cover with cold water.
- Bring the water to the boil then strain the mandarins, discarding the water. Return the mandarins to the pot and repeat the process. Do this a total of five times.
- In a separate pot bring the water and sugar to a boil, reduce the heat and cook for 2 minutes. Remove from the heat and allow the syrup to cool.
- Put the mandarins and the sugar syrup into a liquidiser and purée until smooth. Slowly pour in the oil and blend. This sauce will keep indefinitely in the refrigerator.