• Adjust the oven rack to the lower middle position. Preheat oven to 325°F.
• Cut bacon crosswise into ¼-inch thick strips (lardons). Heat a large Dutch oven over medium heat and add 1 tablespoon of olive oil. Once shimmering add the bacon and cook until lightly browned. Use a slotted spoon to remove the lardons to a large bowl and set aside. Leave the fat in the pot.
• Dry the beef cubes with paper towels. Re-heat the Dutch oven over medium-high heat until almost smoking. Add the beef in batches, a few pieces at a time, and cook until browned on all sides. Don’t crowd the pan as the beef will not brown properly. Remove the browned beef to the bowl with the lardons. Repeat with any remaining beef cubes.
• Add the carrots and chopped onions to the now empty pot. Cook the vegetables over medium-high heat stirring frequently until lightly browned. Remove all but 1 tablespoon of the fat and discard.
• Add the tomato paste and garlic to the carrots and onions. Cook and stir for a few minutes or until the garlic is fragrant and the tomato paste slightly darkens in color.
• Return the beef and bacon to the pot and season with ½ teaspoon salt and ½ teaspoon pepper. Sprinkle the flour over the beef and toss to coat.
• Cook over medium heat, stirring occasionally, until a dark fond forms on the bottom of the pot, about 5 minutes.
• Pour 1 cup of wine over the beef and deglaze the pot by scraping the bottom to release any browned bits. Add the remaining 2 cups of wine and 3 ½ cups of stock enough to cover the beef. Add the thyme and bay leaf and bring to a simmer.
• Once simmering cover the Dutch oven and transfer to the oven. Cook so the broth simmers slowly for 3 to 4 hours. Reduce the heat or increase as needed to ensure the stew simmers but doesn’t boil. Continue to cook stirring gently a few times, until the beef is very tender and pierces easily with a fork.

While the beef is cooking prepare the onions and mushrooms.

• Heat a large nonstick skillet over medium-high heat. Add 1 ½ tablespoons butter and 1 ½ tablespoons oil until bubbling. Add the onions and reduce the heat to medium. Sauté the onions for about 10 minutes, carefully rolling them around so they brown as evenly as possible.
• Add ⅓ cup of beef broth, ¼ teaspoon salt and ¼ teaspoon pepper, thyme sprigs and bay leaf. Cover and simmer slowly for 30 minutes or until the onions are tender but still hold their shape and the liquid has evaporated. Discard the thyme sprigs and bay leaf and transfer the onions to a bowl.
• Heat the remaining 1 ½ tablespoons of butter and 1 ½ tablespoons of oil in the now empty skillet over medium-high heat. When the butter stops bubbling add the mushrooms. Toss the mushrooms to coat then leave in a single layer to brown without stirring, about 5 minutes. Once browned on one side, stir and continue cooking until the moisture is released and then evaporates.
• Remove the cooked mushrooms to the bowl with the onions. Cover and refrigerate until needed.

Assemble the stew

• Once the beef is tender remove the pot from the oven. Allow the stew to rest for 5 minutes then tilt the pan to skim off and discard any fat that pools on top. Don’t worry if you can’t get it all, a little fat is okay.
• Set the Dutch oven on the stovetop over medium-low heat. Add the pearl onions and mushrooms and stir gently to combine. Cover and simmer for 3 or 5 minutes or until heated through.
• Serve directly from the Dutch oven or arrange the stew on a platter surrounded with boiled potatoes, buttered noodles or rice. Garnish with fresh parsley leaves and serve.