Preheat the oven to 325 F (165 C). Pat the beef dry and season with salt and pepper. Cook the bacon in a Dutch oven until crisp; transfer it to a plate.
Brown the beef in the bacon fat in batches, adding the olive oil if needed. Transfer the beef to the plate.
Build the braise:
Cook the onion and carrots in the pot until lightly browned. Add the garlic and flour and stir for 1 minute.
Pour in the wine, scraping up the browned bits. Add the stock, tomato paste, thyme, bay leaves, bacon, and beef. Bring to a simmer.
Cover and braise in the oven for 2 hours, or until the beef is fork-tender.
Finish and serve:
Sauté the mushrooms and pearl onions in a skillet until browned and tender. Stir them into the finished stew and simmer uncovered for 10 minutes.
Remove the bay leaves, adjust the seasoning, scatter with parsley, and serve hot with bread or potatoes.
Notes
Dry the beef thoroughly before browning for better color.
The stew should barely simmer in the oven, not boil hard.