Place the diced venison in a bowl ready to marinate. Pour over the Guinness and the red wine, adding the bay leaves, thyme, juniper berries, onion and garlic.
After marinating for 45 mins drain the meat and pat dry. Toss the meat in the flour and place in a hot pan with the butter and olive oil, when the venison has browned add in the marinade- this will be the sauce.
Bring the sauce to the boil and let simmer for 2 – 3 hrs. When you are ready serve up the casserole with a nice chunk of fresh rustic bread.