Brown the Beef: In a large Dutch oven, heat the olive oil over medium-high heat. Brown the beef cubes in batches to avoid overcrowding the pan, about 4-5 minutes per batch. Remove the beef and set aside.

Sauté Vegetables: In the same pot, add the diced onions and carrots. Sauté for 5-7 minutes, until softened. Add the garlic and cook for 1 minute more.

Make the Sauce: Sprinkle the flour over the vegetables and stir to coat. Cook for 1-2 minutes. Slowly pour in the wine while stirring, scraping up any browned bits from the bottom of the pot. Stir in the beef broth, tomato paste, thyme, and bay leaves.

Simmer: Return the beef to the pot, ensuring it’s covered with liquid. Bring to a boil, then reduce heat to low. Cover and simmer for 2-3 hours, or until the beef is tender.

Cook the Mushrooms and Onions: While the stew is simmering, melt butter in a pan over medium heat. Add the pearl onions and cook for 8-10 minutes, until lightly browned. Add the sliced mushrooms and cook for another 5 minutes until the mushrooms are tender.

Combine: Add the cooked onions and mushrooms to the stew, and cook for an additional 20-30 minutes, allowing the flavors to meld. Season with salt and pepper to taste.

Serve: Garnish with chopped fresh parsley and serve with crusty bread or over mashed potatoes.