Instructions

1. Chop the spring onion, garlic and chilli.
2. Heat the oil in a heavy-based saucepan over medium heat.
3. Add the onion, garlic and chilli and gently cook for 5 minutes until the onion has softened.
4. Add the mustard seed, stir for half a minute then add the sugar, raisins and vinegar. Let it bubble for a few seconds.
5. Cover with a lid, turn down the heat and gently simmer until the liquid has evaporated and the onions are very soft and sticky.
6. Season with salt and pepper then transfer to a sterilised jar or a small bowl.