Preheat your oven to 350°F (175°C). Gather your ingredients to be ready.

In a Dutch oven over medium-low heat, add the chopped bacon and cook until browned, about 5-7 minutes. Remove bacon and set aside, leaving drippings.

Season beef chunks with salt and pepper. Increase heat to medium-high and sear beef in batches for about 8-10 minutes until browned. Transfer beef to plate with bacon.

Lower heat to medium, add unsalted butter, and toss in onions and carrots. Sauté for 5-7 minutes until caramelized. Add garlic and tomato paste, stirring for 2-3 minutes.

Sprinkle flour into the mixture, stirring continuously for 2-3 minutes to thicken sauce.

Slowly pour in Burgundy wine and beef stock, scraping the bottom for flavors. Add bouillon, thyme, and bay leaves. Return seared beef and bacon to the pot.

Cover and place in oven. Braise for 2.5 hours until beef is tender.

Meanwhile, in a skillet, melt remaining butter and sauté mushrooms and pearl onions until golden brown, about 8-10 minutes. Season with salt and pepper.

After braising, stir in sautéed mushrooms and onions. Return pot to oven uncovered for another 45-60 minutes until beef is fork-tender.

Remove from oven and let sit covered for 30 minutes before serving.