2tbspBalsamic vinegar(or white wine vinegar if you prefer)
1tbspJack Daniels(or any bourbon/ whiskey you prefer)
2tbspMaple syrup
100mlStrong black coffee
½tspGround black pepper
Instructions
Prep
Chop the onion finely
Chop the bacon finely into small pieces
Weigh/ measure the other ingredients
To Cook
Over a medium heat, stirring often, fry the bacon for 5-10 minutes until crisp. Remove from the pan using a slotted spoon and place to one side, leaving the bacon fat in the pan
Turn down the heat to low and add the onions with a pinch of salt, cook for about 15 minutes, stirring frequently, until they begin to caramelise. Add back the bacon and all the other ingredients
Cook slowly for 25 minutes or so, stirring occasionally until it reaches a thick and syrupy consistency. Leave to cool
To Store
When cool, place in a sterilised jar and store in the fridge for up to a month (though there's no chance it will remain uneaten for that long)