Step 1

Wash and scrub the oranges to remove the wax on the skins and cut off the tops and bottoms. Quarter, remove any seeds and slice as thinly as possible. Put into a saucepan together with the juice of 1 lemon and 2 cups of water. Bring to the boil, then simmer for 2 hours with the lid closed.

Step 2

Take off the lid and increase the temperature to medium. Add the sweetener and let the marmalade bubble away and reduce, stirring regularly (especially towards the end). Adjust sweetener, adding more if required.

Step 3

Fill the marmalade into glass jars and store in the fridge.