Homemade chipotle molasses BBQ sauce - Good Food Middle East

Ingredients

• 1 tbsp olive oil
• ½ small onion, finely chopped
• 2 garlic cloves, chopped
• 100ml apple cider vinegar
• 85g dark soft brown sugar
• 1½ tsp mustard powder
• 1½ tsp smoked paprika
• 1½ tsp celery salt
• 2 tsp hot chilli powder
• 1 tbsp Worcestershire sauce
• 2 tsp chipotle paste
• 2 tbsp tomato purée
• 1 tbsp liquid smoke (optional - see tip, below)
• 350ml passata
• 75ml black treacle