3 lbs. Seville Oranges
3 liters. Water
3 kgs. Sureset Sugar.

Put the whole Oranges into a large pot with the water and simmer together for about 90 mts. or until the skin is tender.
Take the oranges out of the water with a slotted spoon and cool; leave the water in the pot.
When they cool halve the oranges and remove the pips.
Either discard these or put them in a little square of muslin tied at the edges to boil with the marmalade.
Now cut the halves of orange as finely or thickly as you like (if you don’t care too much about the appearance you can chop them up roughly in batches in a food processor).
Put these back into the orange water and add in the sureset sugar.
Bring gradually back to the boil (with the little bag of pips if you are using them) stirring to dissolve the sugar.
Let it boil well for 5 mts. test for setting on a cool saucer.
It should take no longer than 10 mts. boiling altogether.
Take out and discard the bag of pips, and pot in the usual way.