Venison sausages with celeriac puree
To make the sausages, melt the butter in a large frying pan on a medium-high heat, then add the diced onion and fry, stirring occasionally, for 8-10 minutes until slightly golden. Set aside.
Meanwhile, in a large bowl, mix together the minced venison, the minced pork, the fresh white breadcrumbs, the beaten egg, the crushed or finely grated garlic, whichever you're using, the chopped rosemary leaves, and the wholegrain mustard. Season with salt and freshly ground black pepper, then add the cooled onions that you fried earlier to the mixture. If the mixture is very wet, add a few more breadcrumbs.
Preheat the oven to 200°C, 400°F, Gas 6. Put a little bit of the mixture in the frying pan and cook it for 1-2 minutes to check for seasoning. Adjust if necessary. Shape the sausage mixture into about 12 sausages. Pour the olive oil into the frying pan and, on a medium heat, brown the sausages on all sides. Then put them on a baking tray and bake in the oven for 10 minutes or until cooked through.
For the puree, place the diced celeriac and the diced potatoes in a large saucepan, then pour over the milk to just cover them. Simmer on a medium-low heat for about 15 minutes, then drain and mash very well. Season with salt and freshly ground pepper, then add the cream and the butter. Unless you're serving the puree immediately, place it in a covered, ovenproof dish and keep it warm in the oven after the heat has been switched off.
Serve the venison sausages with a good spoonful of celeriac puree.