Start by patting the chuck roast cubes dry with paper towels, then season them generously with salt and pepper.

In a large Dutch oven, heat a mix of olive oil and butter over medium-high heat until shimmering. Add the seasoned beef in batches, browning each side for about 3-4 minutes until deep, golden crust forms.

In the same pot, add the diced bacon and cook over medium heat until crispy and browned, about 5-7 minutes. Add the sliced onions and sauté for another 5-6 minutes until they soften and begin to caramelize.

Stir in the minced garlic and cook for an additional minute. Sprinkle the flour over the mixture and stir well to combine, cooking for about 2 minutes.

Carefully pour in the cognac while scraping the bottom of the pot. Allow it to cook off for about 1-2 minutes. Then, mix in the tomato paste, beef broth, red wine, and fresh thyme. Return the seared beef to the pot.

Cover the pot with a tight-fitting lid and reduce the heat to low. Let the stew simmer for approximately 2 hours, stirring occasionally, until the beef is fork-tender.

While the beef is simmering, heat a separate skillet over medium heat. Add a drizzle of olive oil and sauté any additional mushrooms and pearl onions until they become golden and tender, about 5-7 minutes.

After the 2-hour simmer, stir the sautéed vegetables into the pot with the beef. Continue to simmer uncovered for another 20-30 minutes, allowing the sauce to reduce and thicken.

Once the sauce has reached your desired consistency, ladle the Beef Bourguignon into hearty bowls. Serve it over garlic-rubbed toasted bread for a rustic touch.