Wash the oxtails in water, lemon and vinegar. Trim any access fat off if desired. Leave the oxtails in a clean bowl.
On a chopping board slice the onions, spring onion and bell pepper. Chop the carrots into large blocks. Dice the garlic and the ginger. Set aside the vegetables.
Next, add the spices into a bowl. Using the pestle and mortar grind the coriander seeds. Set aside.
Throw in about ½ the spices into the bowl with oxtail. Drizzle a bit of oil and rub the spices into the meat. Cover in clingfilm and leave in the fridge to marinate overnight or for 3-5 hours.
On medium heat, throw in the oil and sprinkle the sugar around the pot. Braise the oxtails in the pot until the oxtails have a beautiful golden/brown colour on all sides.
Set aside the oxtails, drizzle in some more oil and fry the vegetables in the same pan. Once the onions become translucent/clear add in the spices. Fry for another minute or two minutes.If the vegetables begin sticking onto the pan pour a little bit of water in. Once the vegetables and the meat have been cooked throw all the ingredients into the slow cooker. Add the water until everything is covered. Set the slow cookers temperature on "High" Set a timer for 5hrs:30min and relax.
Once the meat + vegetables are tender and soft turn the slow cooker off. Top this curry off with fresh corrinader or mint. Serve with rice or rotie. Enjoy!