Add all the ingredients to a saucepan, whisk and then heat over medium.

Once it starts bubbling, kill the heat. Taste and adjust for seasoning. It will thicken as it cools, but you can thicken it more by heating it and reducing for 5 - 10 minutes if desired (mine was plenty thick though!)

Store in a mason jar or similar in the fridge for up to 1 week (possibly longer but I always eat it before then!)