Cut the butternut squash into 12 thick, equal pieces, reserving the trimmings for the purée

For the butternut squash purée, place the butternut trimmings in a pan and gently cook with a little butter, being careful not to let it colour. Once the squash is soft, transfer the contents of the pan to a blender and blitz until silky smooth

Place a large pan over a medium heat and add a little oil and butter. Season the venison with salt and pepper and place in the pan. Colour on all sides for 4-5 minutes, turning the meat continuously. Take care not to overcook it, as the venison will dry out - aim for a nice pink finish

Once the meat is coloured on the outside but rare inside, leave to rest in a warm place - above an oven or under a cloth

Using the same pan, add a little oil and colour the chunks of butternut squash, then reduce the heat slightly and add the chicken stock. Cook until almost soft, then add the girolles and increase the heat

Cook for a minute, tossing the pan 2 or 3 times. Add the treviso leaves and keep on the heat for a further minute until the leaves have become limp and wilted

Add a squeeze of lemon, another knob of butter, the chopped parsley and salt and pepper

To serve, heat the butternut squash purée until warm and spoon around the plate. Arrange the butternut squash, treviso, girolles and venison onto plates, then finish with a small amount of the cooking juice and some rock salt. Serve immediately