6 roughly chopped toasted cobnuts, plus 4 cobnuts to serve
salt and freshly ground black pepper
Preheat the oven to 200C/180C Fan/Gas 6.
Place the onions in a roasting tin and roast until charred and soft – this will take about an hour. Remove and set aside.
Season the venison with salt and freshly ground black pepper and place in a roasting tin. Roast for 6-8 minutes until rare and remove from the oven.
Add the Madeira, butter, thyme, garlic and demi-glace to the venison. Baste the meat, cover and leave to rest in a warm place.
Lightly fry the corn in the thyme and butter in a medium frying pan. Add the stock and cook until the volume of liquid has reduced to nothing. Add the cream and bring back to the boil. Add the chopped tarragon and toasted cobnuts.
Cut open the reserved onions and remove the onion petals. Serve slices of the venison with the corn, garnished with the onion petals and some grated cobnuts over the top.