Step 1

Preheat the oven to 180ºC/350ºF/gas

Step 2

Place the venison bones in a large, deep roasting tray. Peel the onion, wash the carrot, then roughly chop with the celery, add to the tray with the flour and toss together. Roast for 1 hour, then use tongs to transfer everything to a big pot. Add enough boiling kettle water to the tray to scrape up the sticky goodness from the base, then pour that into the pot with the wine. Just cover with boiling water, then simmer on a low heat for 2 hours, skimming the surface and topping up the water occasionally, if needed. Carefully remove the bigger bones, then strain the sauce through a coarse sieve into a pan. Simmer on a low heat to the consistency of your liking, then turn the heat off. Get your meat out of the fridge and up to room temperature before you cook it. Crush the coffee beans and peppercorns in a pestle and mortar until fine, pick and pound in the rosemary leaves, then peel and crush in the garlic to make a rough paste. Finely grate in the orange zest and muddle in the balsamic. Cut each venison loin in half to give you four pieces, then rub the paste all over the meat. Divide the prosciutto between two large sheets of greaseproof paper, slightly overlapping the slices. Place two pieces of venison on top of each other on each one, spooning the meat so the thick and thin ends even each other out. Roll up in the prosciutto, tucking in the ends, tie with string at regular intervals to secure the prosciutto in place, then put on a roasting tray. To cook, drizzle the loins with a little oil, then roast in a preheated oven at 180ºC/350ºF/gas 4 for 30 minutes, turning every 10 minutes. Remove and rest for 10 minutes. Meanwhile, bring the sauce back up to a simmer, snap in the chocolate, add the butter, and whisk until smooth. Leave for a few minutes, then season to perfection. Remove the string from the venison, then carve and serve with the sauce. Delicious with celeriac mash and steamed seasonal greens.