Step 1

Place the oil in a saucepan over low heat, add the onion and cook for 5 minutes until softened . Add all the other ingredients – except the gherkins - and bring to the boil. Reduce heat to medium and cook for 15-20 minutes, stirring, or until slightly thickened.

Step 2

Allow to cool for about 20 minutes. Place into a blender, together with the gherkins until smooth. Return to the saucepan and bring to a simmering boil.

Step 3

Put into sterilised, sealed bottles. Once opened, refrigerate.