Preheat oven to 150°C fan-forced. Pat the beef cubes dry with paper towel and season generously with salt and pepper.
Heat the olive oil in a large Dutch oven over medium-high heat. Brown the bacon lardons until crisp, then remove with a slotted spoon.
Brown the beef in three batches, four minutes per side, until deeply caramelised. Do not crowd the pan. Set aside with the bacon.
Reduce heat to medium. Add the onion and carrots, cook 6 minutes until softened. Add the garlic and tomato paste, cook 1 minute.
Sprinkle in the flour, stir for 1 minute. Pour in the red wine, scraping the bottom of the pot. Reduce by half over high heat (about 8 minutes).
Return the beef and bacon to the pot. Add the stock and bouquet garni. Bring to a simmer, cover, and transfer to the oven.
Cook for 2.5 hours, undisturbed. Meanwhile, melt half the butter in a frying pan and brown the pearl onions until caramelised. Set aside.
Brown the mushrooms in the remaining butter until golden. Set aside.
After 2.5 hours, add the onions and mushrooms to the pot. Cook uncovered for the final 30 minutes.
Discard the bouquet garni. Taste for salt. Scatter with parsley and serve with mashed potato or crusty bread.