Transfer the meat from the pan to a dish and set aside. Add the remaining 4 tablespoons of oil to the pan used to brown the beef. Heat over a medium-high heat and add the onion-tomato paste. Add the seasonings, stir and then fry for 5 minutes until fragrant. Add the beef and 1.5 litres of water and cover the pan with a lid. Turn the heat down to medium-low and cook for 2½ hours until the beef is tender and falling apart, stirring occasionally to stop the curry from sticking to the base of the pan.