Heat a dry pan over medium flame and gently toast 2 tsp fennel seeds until they release their aroma.
Place the fennel seeds along with 1 cinnamon stick, 2 tsp whole cloves, 2 whole star anise and 4 Indonesian long peppers into a mortar and pestle and grind until it forms a fine powder. Alternatively, place into a high speed blender and pulse until it reaches the desired consistency.
Place 450 grams dark brown sugar, 125 ml apple cider vinegar, 125 ml Scottish rapeseed oil, 1 tsp smoked sea salt, 4.5 tsp garlic granules, 142 grams tomato puree into a small saucepan over a medium heat along with all of the ground five spice powder. Bring to a simmer, stirring occasionally, and cook for five minutes.
Pour into hot sterilized jars and seal. Will keep for a few weeks in the fridge.