- Chop the onion and garlic and put in a pan with just enough vinegar to keep it wet.
- Cook over a medium to low heat for about 10 minutes, stirring now and then.
- When the onions are soft and caramelised add the remaining ingredients and keep on a soft boil for 1 hour with a lid on.
- Carefully blend the sauce. I use a stick blender in the pan.
- Cook for a little longer to get the desired thickness.
- Pour into sterilised bottles to store.