Preheat your oven to 350°F (175°C).
Season the beef cubes with salt and pepper. In a large Dutch oven, heat 2 tablespoons of olive oil over medium-high heat. Sear the beef in batches until browned on all sides, about 5 minutes per batch. Remove the beef and set aside.
In the same pot, add the diced bacon and cook until crispy. Remove the bacon and set aside with the beef.
Add the chopped onion and carrots to the pot. Sauté for about 5 minutes until softened. Stir in the minced garlic and tomato paste, cooking for an additional minute.
Pour in the red wine, scraping the bottom of the pot to release any browned bits. Bring to a simmer and cook for 5 minutes.
Return the beef and bacon to the pot. Add the beef broth and bouquet garni. Bring to a gentle boil, then cover and transfer to the preheated oven. Cook for 2 to 2.5 hours, or until the beef is tender.
In the last 30 minutes of cooking, heat the remaining tablespoon of olive oil in a skillet over medium heat. Add the quartered mushrooms and sauté until browned. Set aside.
Once the beef is tender, remove the pot from the oven. Discard the bouquet garni. In a small bowl, mix the flour and butter to form a paste. Stir this mixture into the stew to thicken the sauce. Add the sautéed mushrooms and stir to combine.
Let the stew sit for 10 minutes before serving. Garnish with chopped parsley.