1. Wash, wipe dry the tomatoes, and cut into fours. Sprinkle the sugar, cover, and leave overnight.
2. On the next day put the tomatoes along with the juice into a thick-bottomed pan and set to boil on gentle heat until the tomatoes are cooked.
3. Add the lime juice and ginger powder, raise the heat and cook until a jam consistency is reached. Test for setting.
4. When done, remove from fire, pour into hot sterilised jars and seal.