Preheat the oven to 150°C (300°F).
In a large Dutch oven, cook the bacon pieces over medium heat until crispy. Remove and set aside, leaving the fat in the pot.
Season the beef cubes with salt and pepper, then brown them in the bacon fat in batches. Remove and set aside.
Add the carrots and onions to the pot, cooking until the onions are translucent.
Stir in the garlic and cook for another minute.
Add the flour and stir to coat the vegetables. Cook for 2 minutes.
Slowly add the red wine, scraping up any bits off the bottom of the pot.
Return the beef and bacon to the pot, and add the beef stock, tomato paste, bay leaves, and thyme.
Bring to a simmer, then cover and place in the oven for 2.5 hours.
Add the mushrooms and continue cooking for another 30 minutes.
Remove bay leaves and thyme sprigs before serving.