For the venison stew with mushrooms, remove tendons and skins from the venison shoulder, wash well with cold water, pat dry with kitchen paper and cut into bite-sized pieces.
Cut the bacon into cubes. Peel and finely chop the onion and garlic. Heat olive oil in a large saucepan and sauté bacon, onion and garlic until translucent. Add the meat and sear on all sides. Season with salt and pepper. Pour the beef broth and wine and simmer at low temperature for 40 to 45 minutes with the lid closed.
Wash and clean the mushrooms and cut them into thin slices. Wash and chop the parsley. Stir in the mushrooms to the ragout and simmer on low heat for another 10 minutes. Season to taste with the soy sauce. Stir the sour cream into the sauce.
Sprinkle the venison ragout with mushrooms with fresh parsley.