Prepare the plums by washing, stoning, and chopping them into chunks.
1 kg Ripe plums
Finely chop onions, garlic, and ginger so they integrate smoothly.
300 g Red onion , 3 cloves Garlic , 25 g Fresh ginger
Place all ingredients in a large, heavy-based saucepan or preserving pan.
300 ml Malt vinegar , 1 tsp Ground cinnamon , 1 tsp Ground allspice , ½ tsp Dried chilli flakes , 1 tsp Salt
Bring to the boil over medium heat, stirring to dissolve the sugar.
500 g Soft brown sugar
Reduce to a gentle simmer, stirring occasionally to prevent sticking.
Cook for 1–1.5 hours until thickened; the chutney should leave a clear trail when you drag a wooden spoon through the pan.
Ladle into sterilised jars while hot, seal immediately, and label.