In a large bowl, combine the flour, salt, and black pepper. Toss the beef cubes in the mixture until well coated.
Heat olive oil in a large skillet over medium-high heat. Add the chopped bacon and cook until crispy. Remove bacon and set aside, leaving the drippings in the skillet.
In the same skillet, brown the beef in batches, ensuring not to overcrowd the pan. Transfer the browned beef to the slow cooker.
In the same skillet, add the diced onion and sliced carrots. Sauté for about 5 minutes until softened. Add the minced garlic and cook for an additional minute.
Pour in the red wine, scraping up any browned bits from the bottom of the skillet. Bring to a simmer, then add the beef broth, tomato paste, thyme, and bay leaf. Stir to combine.
Pour the wine mixture over the beef in the slow cooker. Add the cooked bacon and quartered mushrooms. Stir gently to combine.
Cover and cook on low for 7-8 hours or on high for 4-5 hours, until the beef is tender.
Once cooked, remove the bay leaf and adjust seasoning if necessary. Serve hot, garnished with fresh parsley.