- Preheat the oven to 180°C.
- Make up the marinade by combining the vinegar, honey, mustard, garlic and seasoning. Add the lamb pieces and rub the marinade into the lamb and the scored fat. Leave to stand for at least 30 minutes.
- Combine the oil, chopped rosemary, salt and pepper, then add the potatoes and stir well.
- Heat a pan (suitable for the oven), add the oil and fry the lamb rumps fat side down for a few minutes until brown, then turn to sear all surfaces of the lamb. Add the potatoes to the pan, fry until lightly browned. Add the rosemary springs and then transfer to the oven to finish cooking for approximately 20 -25 minutes until the potatoes are cooked.
- Allow meat to rest for 5 minutes before carving. While resting make a gravy and stir the redcurrant jelly into the gravy.
- Serve with green vegetables (eg. broccoli).