In a bowl large enough to hold all the meat, mix the chopped onion, garlic and chives with the vinegar and cloves. Add the goat and marinate for about 20 minutes.
Meanwhile, heat the oil in a large flameproof casserole dish over a medium heat. Add the sliced onions and fry for 10 minutes. Stir in the curry powder and cook for a further 1 minute. Add the goat and crumble in the lamb stock cube. Stir in the sprigs of rosemary, oregano and parsley. Add 700ml/1¼ pint water and season with salt and pepper. Mix everything together and bring to the boil. Reduce the heat, cover with a lid and simmer for 1 hour.
Remove the lid and continue to simmer for a further 1–1½ hours, or until the meat is very tender and the sauce reduced.
While the curry is cooking, place all the rice ingredients in a lidded saucepan with 450ml/16fl oz water. Stir well and bring to a boil. Reduce the heat, cover and simmer for 6 minutes.
Turn off the heat and leave to stand, covered, for a further 5–6 minutes, or until tender and the liquid has been absorbed.
Stir the coriander through the curry and fluff up the rice before serving.