Preheat the oven to 180°C/gas mark 4

To begin, make the sauce. Place a deep roasting tin over a moderate heat on the hob and a good tablespoon of vegetable oil. When hot, add the venison trimmings and bones and transfer the tray to the oven. Roast for 25–30 minutes, or until the bones are golden

After this time, add the chopped carrot and beetroot to the tin and return to the oven for 6–8 minutes

Add the butter, shallots, mushrooms, garlic and fresh herbs then return to the oven for another 6–8 minutes, taking care that these don't over-brown

Add the sherry vinegar to the tin to deglaze it, scraping up any browned residue from the base of the tin. Stir in the brown chicken stock and return the whole tin to the oven for another 30 minutes

For the purée, place the celeriac and the chestnuts (reserving a few for garnish) in a snug-fitting pan and cover with the milk and cream. Season with salt and pepper, place over a moderate heat and bring to a simmer

Cook until the celeriac and chestnuts are very tender (15–20 minutes) then drain and reserve the cooking liquid

Transfer the celeriac and chestnuts to a blender and blitz to a smooth purée, adding enough of the cooking liquid to achieve the right consistency. Pass the mixture through a fine sieve or chinois to ensure it is completely smooth, then reserve until ready to serve

Once the 30 minutes is up, remove the sauce tin from the oven and transfer the contents to a deep pan, adding the cloves, peppercorns and juniper berries. Cover the pan with cling film and allow to stand for 45 minutes

While the sauce is standing, add the sherry and cognac to a pan, bring to the boil and reduce by half. Set aside until ready to finish the sauce

For the braised potatoes, first create a shallot compote by adding 40g of the butter and 1 teaspoon of the thyme leaves to a pan. Place over a gentle heat, add the sliced shallots and a pinch of salt and sweat the shallots down without colouring

When totally soft, add a spoonful of the chicken stock and simmer for 10 minutes to create a moist texture. Set aside

Preheat the oven to 180°C/gas mark 4

Cut the potatoes into 5mm slices and use a 4cm pastry cutter to cut out 16 rounds in total. Rinse well under cold water and pat dry with kitchen paper

Add the remaining 40g of butter to a large frying pan and place over a moderate heat. Brown the potato rounds on both sides in the butter, then add the remaining thyme, chicken stock and the cooked shallot compote

Cover the pan with tin foil and transfer to the oven to cook for 8–10 minutes until the potatoes are tender and glazed

Once the sauce has stood for its allocated time, strain the sauce mixture through a fine sieve or chinois into the reduced alcohols. Mix well, check for seasoning then keep warm until ready to serve

To cook the venison, heat a large cast iron pan over a medium-high heat for 1 minute then add the vegetable oil to heat through for another minute. Season the venison loins with salt and add to the hot pan, browning on all sides before adding the thyme and garlic, with a little more oil is needed

After cooking for a few more minutes, add the diced butter and allow to foam. Baste the meat with the butter and keep turning the loins every minute or so to cook evenly and to coat in the thyme and garlic butter. Transfer to a warm plate with the juices from the pan and allow to rest for 6–8 minutes

While the meat is resting, add a knob of butter to a hot frying pan and sauté the trompette mushrooms and diced celeriac until softened. Blanch the kale in boiling salted water and drain well

To serve, slice the venison loins into thirds and arrange on servings plates with the blanched kale scattered over. Add 4 of the cooked potatoes to each plate and spoon some of the buttery celeriac and trompettes over each

Add a quenelle of the celeriac and chestnut purée and top with a few slices of the reserved chestnuts. Spoon over some of the warmed sauce and serve