The day before cooking
To start the dish, place the diced venison , wine, vegetables, (but not the celeriac), garlic and spices in a large, non-metallic container or dish. Tie together the herbs with string, add to the dish and cover the container. Place in the fridge to marinate for 24 hours.
Preheat the oven to 160C. The next day, remove the venison from the dish and set aside. Carefully drain the vegetables, reserving the liquid in a separate bowl, and set to one side, I know this is a bit time consuming but well worth it as marinading the meat adds to the flavour. Add 1 tablespoon of oil and the butter to a heavy-based, ovenproof casserole dish and heat until almost smoking, then add the vegetables and bacon, cooking until nicely caramelised.
Season the flour with freshly milled pepper and fine sea salt, dust the diced venison with the seasoned flour. In a frying pan, brown the venison a handful at a time and add to the casserole, when you are browning the final batch of venison add the tomato puree to allow it to cook slightly with the meat. Pour the red wine and stock into the casserole dish along with the redcurrant jelly, juniper berries and salt and pepper. Bring to the boil and stir well. Put the lid on the casserole and place in the middle of the oven - cook for approximately 90 minutes or until the meat is tender.
Check the tenderness of the venison, it may need a little longer as all oven temperatures vary. If it's lovely and succulent check the seasoning and then serve.