Combine venison, wine, onion, juniper, and bay leaves in a bowl. Marinate refrigerated at least 6 hours.
Remove venison, patting dry, and reserve the marinade.
Heat oil in a large pot over medium-high heat. Brown venison in batches, 4–5 minutes per batch. Set aside.
Add mushrooms to the pot and cook 6–8 minutes until browned.
Stir in tomato paste, then add the reserved marinade and broth.
Return venison to the pot, bring to a simmer, cover, and braise 1 hour 30 minutes until tender.
Stir in cream and warm through without boiling.
Season with salt and pepper and serve hot.