Prepare your jars by washing them well and sterilise by drying in a 150°C oven for 10 minutes.
In a clean, dry pan, toast the coriander and cumin seeds until fragrant and just beginning to pop. Set aside.
Peel and slice the onions. Weigh the onions and then weigh out the same amount of jam sugar.
Place the onions, cumin seeds, coriander seeds, salt and vinegar in a saucepan over medium-high heat. Cover and simmer for 15 minutes.
Add the sugar and stir over a low heat until all the sugar dissolves. You can feel the sugar on the bottom of the pan like sand.
Increase the heat and bring to a boil. Boil rapidly for exactly 4 minutes. Use a kitchen timer.
Skim the marmalade with a ladle.
Stir through the molasses.
Allow to stand for 15 minutes for the onion to settle and distribute evenly.
Pour the hot marmalade into warm sterilised jars and cover immediately.
Allow to cool completely, then label and date the marmalade and store in a cool, dark place. Refrigerate after opening.
Recipe supplied by Rozanne Stevens