Preheat your oven to 325°F (160°C).
In a large Dutch oven, cook the diced bacon over medium heat until browned and crisp. Remove and set aside, leaving the fat in the pot.
Increase heat to medium-high. In the same pot, brown the beef cubes in the bacon fat in batches. Season with salt and pepper.
Remove the beef and set it aside. In the same pot, add olive oil if necessary and sauté the onions and carrots until soft, about 5 minutes.
Add garlic and tomato paste. Cook for an additional 2-3 minutes, stirring frequently.
Return the beef and bacon to the pot. Pour in the wine, scraping up any browned bits from the bottom.
Add the beef stock, thyme, and bay leaves. Bring to a simmer, then cover and transfer to the preheated oven.
Cook in the oven for about 2.5 to 3 hours, or until the beef is fork-tender.
While the beef is cooking, sauté the pearl onions and mushrooms in a separate pan until browned and tender. Set aside.
After the beef is tender, stir in the onions and mushrooms. Simmer on the stovetop for about 20 minutes to meld flavors before serving.
Serve hot, garnished with fresh parsley if desired.