For 10 people
Wash clementines; remove seeds; slice very thinly (keep peel).
Cover with water and simmer 40 minutes until peel is tender; cool slightly.
Weigh fruit and cooking liquid; add an equal weight of sugar and the juice of a lemon.
Boil briskly 20–30 minutes to 104–105°C; jar hot into sterilised jars and seal.