Using a pestle and mortar crush the cardamon pods and cloves together, discarding the cardamon shells.
You could also use the end of a rolling pin if you don't have a pestle.
In a food processor, add the chopped onions, garlic cloves, fresh ginger - and all the spices - the cumin, turmeric, chilli powder, salt, crushed cloves and cardamom. Then a splash of vegetable oil.
Blitz until you get a fine paste. Add a little more if you think the paste isn't coming together as well as it should.
Then add the paste, the pork meat, chopped potatoes, tinned tomatoes, chicken stock, vinegar and cinnamon stick into the slow cooker.
Give all the ingredients a good stir then cook on low for 8 hours [or high for 4-5 hours].
Serve with fresh coriander sprinkled on top, rice, naan and poppadoms.