Preheat the oven to 325°F (165°C).

Heat 1 tablespoon of oil in a large Dutch oven over medium heat. Add the bacon and cook until crispy. Remove the bacon and set aside, leaving the fat in the pot.

Pat the beef dry with paper towels and season generously with salt and pepper. Working in batches, add the beef to the pot and sear on all sides until browned, about 3-4 minutes per side. Transfer to a plate.

Add the carrots and onions to the pot and cook until the onions are translucent, about 5 minutes. Add the garlic and cook for another minute.

Sprinkle the flour over the vegetables and stir to coat. Cook for 1-2 minutes.

Slowly add the red wine, scraping the bottom of the pot to release any browned bits. Add the beef stock, tomato paste, thyme, bay leaves, and return the beef and bacon to the pot. Bring to a simmer.

Cover the pot and transfer to the oven. Cook for 2.5-3 hours, or until the beef is very tender.

About 1 hour before the stew is done, heat the remaining oil in a large skillet over medium heat. Add the mushrooms and cook until browned and have released their moisture, about 10 minutes. Add to the stew for the last hour of cooking.

In the same skillet, add the pearl onions and cook until lightly browned, about 8-10 minutes. Add to the stew for the last 30 minutes of cooking.

Remove the bay leaves and thyme sprigs. Taste and adjust seasoning if necessary.

Serve hot, garnished with fresh parsley, alongside mashed potatoes or crusty bread.