Ingredients 

2 medium onions, thinly sliced

1 clove garlic, crushed 

Generous pinch of salt

2 tbsp oil 

3 tbsp balsamic vinegar 

2 tbsp brown sugar 

Place onion, garlic, salt and oil in a heavy based saucepan. Simmer until onion is soft over low heat. Add vinegar and sugar to the pan. Continue to cook over low heat until the sauce thickens and onion if fully cooked. 

Store in a steralised jar in the fridge for 2 weeks.