Method
1. Cooking indoors:
Preheat your oven to 180°C/Fan 160°C/Gas 4. Remove all packaging and string from the venison haunch and pop into a roasting tin. Rub with 1 tbsp olive oil and some salt and pepper. Let the joint sit for 30 mins to come to room temperature.
2. Slide into the hot oven and roast for 40 mins for medium-rare, or add 10-15 mins for a more well done roast. Pop on a plate to rest for 30 mins.
3. While the venison rests, halve and stone the plums then dice them. Peel and finely chop the red onion. Pick the leaves from the thyme sprigs.
4. Pour 1 tbsp oil into a pan and warm it over a medium heat. Add the onion and thyme leaves along with a pinch of salt and pepper. Fry for 8-10 mins, stirring, till softened, then add the plums and stir in 1 tbsp each of the sugar and mustard, and 2 tbsp of cold water. Cover and reduce to a low heat and cook for 10 mins, stirring occasionally, till the plums have started to dissolve into a sauce.
5. Serve the venison in thin slices, with the plum sauce on the side.
6. Cooking outdoors:
Light your barbecue and let it cool to a medium heat. Unwrap the meat and unroll it to flatten out. Rub with 1 tbsp olive oil and a good pinch of salt and pepper.
7. Place the joint on the hottest part of the barbecue and cook for 2-5 mins each side, till coloured. Move to the coolest part and cover the barbecue with a lid. Barbecue for 30-35 mins, then pop on a board. Rest for 20 mins.
8. Pour 1 tbsp oil into a pan and warm it over a medium heat. Add the onion and thyme leaves along with a pinch of salt and pepper. Fry for 8-10 mins, stirring, till softened, then add the plums and stir in 1 tbsp each of the sugar and mustard, and 2 tbsp of cold water. Cover and reduce to a low heat and cook for 10 mins, stirring occasionally, till the plums have started to dissolve into a sauce.
9. Serve the venison in thin slices, with the plum sauce on the side.