Photograph: Jenna Leiter
Dissolve the sugar in 8 tablespoons of water over a medium heat in a large, heavy-based saucepan. Meanwhile prepare the tomatoes. Make a cross in each one at either end. Drop them into boiling water for 1 minute, or until the skins start to split, then remove them with a slotted spoon and peel. Discard the green cores and dice the flesh into 1cm cubes. Remove most of the seeds, but don't worry about some of them being included.
Add the tomatoes to the sugar syrup in the pan, pour in the vinegar and add the chilli and ginger. Season with salt and pepper. Bring to the boil, stirring, then reduce the heat and simmer for 30-45 minutes or until the jam reaches the trail stage. Spoon into warm, sterilised jars and seal straight away. Put on the lids.
This recipe is taken from The Gentle Art of Preserving by Katie and Giancarlo Caldesi