Heat a large pot or large Dutch oven over medium-low heat. Add the bacon and cook until the fat renders. Remove the bacon from the pot and set it aside while reserving the fat in the pot.
Increase the temperature to medium-high heat. Once the bacon fat starts to slightly smoke, add the venison and season with salt and ground black pepper.
Cook the deer meat on all sides until it is golden brown. Remove the meat from the pot and set aside.
Lower the heat to medium low. Add the onions, celery, mushrooms and minced garlic to the same pot. If the mixture seems dry, add a tablespoon of olive oil.
Cook for 6 minutes while stirring occasionally and scraping any brown bits from the bottom of the pan. This will take around 6 minutes.
Place the meat back to the pot. Add all of the remaining ingredients except the carrots and barley.
Cover with a lid and bring to a slow simmer. Cook gently for around 2 hours or until the venison is almost fall-apart tender.
Add the carrot and the barley to the pot and cover with the lid. Simmer until the carrots are fork tender. Add a little more stock or water if needed.
Remove the bay leaves and the thyme springs from pot. Season the soup with salt and pepper to taste.
Serve with crusty bread, sliced green onion and my favorite, fresh c