The Ultimate Barbecue Sauce

Name: The Ultimate Barbecue Sauce
Prep time: 10 min
Cook time: 2 h
Total time: 2 h
Yield: 600 g
Ingredients: 500 g passata; 250 g water; 70 g onions; 100 g Demerara sugar; 200 g malt vinegar; 15 g tomato purée; 65 g golden syrup; 15 g Worcestershire sauce; 15 g soy sauce; ½ tsp smoked paprika; ½ tsp chilli powder; ½ tsp fine sea salt; 1 tsp Dijon mustard; 2 garlic cloves; ½ whole nutmeg; 4 cloves; 2 star anise; 2 dried bay leaves