Clear breakfast marmalade

• 1.8 kg (4 lb) Seville oranges
• either 6 limes and

Pour boiling water over the fruit, which makes it easier to peel. Peel the fruit very thinly with a peeler. Coarsely chop the fruit, with its pith, and put it with its pips, into a large pan with 2.9 litres (5 pints) of water, bring to the boil and cook, covered, for 2 hours. Cut the peel into fine, even shreds and put it in another pan with 1.2 litres (2 pints) of water and cook, covered, for