Jane from our Cookery School has shared her trusty Jane Grigson recipe, with a few amendments.
1kg of Seville oranges
950g jam sugar
950g caster sugar
Halve the oranges and squeeze out the juice and pips, tie the pips and any other pith in a piece of muslin.
Slice the orang peel as thinly as you like and put it in a pan with the fruit juices, muslin bag and the water. Simmer gently for 2 hours until the peel is really soft and the liquid has reduced by half.
Remove the muslin bag and squeeze the juices back into the pan. Add the sugar.
Heat gently, stirring until the sugar has dissolved, then boil rapidly for 15 minutes or until setting point is reached. Remove any scum with a slotted spoon, then jar up as with any other preserve.