Preheat the oven to 325°F
Pat the beef dry with paper towels, season with salt & pepper; set aside.
3 lbs. boneless beef chuck, freshly ground black pepper, kosher salt
In a small bowl, combine the flour, salt and pepper; set aside.
2 tbsp all-purpose flour
Add the bacon to a Dutch oven set over medium heat. Cook until the fat has rendered and use a slotted spoon to transfer the bacon pieces to a paper towel-lined plate.
8 slices bacon
Add 1-tablespoon canola oil to the pot and wait 30 seconds to allow the oil to heat. Add about 1/3rd beef cubes to the pot, turning as needed, to sear all sides. Repeat with remaining beef searing 1/3rd of the beef at a time. Transfer the beef to the same plate with the bacon.
1 tbsp canola oil
Add the carrots and chopped onions to the Dutch oven. Sprinkle with 1 tsp kosher salt and ½ tsp freshly ground black pepper. Cook 8-12 minutes or until the vegetables have lightly browned. Add half the minced garlic and cook another 30 seconds.
5 carrots, 1 large yellow onion, 4 cloves garlic minced
Add the beef and bacon back to the pot with the vegetables and mix. Sprinkle flour over the meat/vegetable mixture and cook, stirring often, for 5 minutes.
Add the wine slowly while deglazing (scraping the flavorful bits) the pan. Add the cognac and enough beef broth to almost cover the meat.
750 ml red wine, 2 cups beef broth, ½ cup cognac
Add the tomato paste, thyme leaves and bay leaf and stir. Bring back to a simmer, cover the pot with a tight-fitting lid and place it in the oven.
1 tbsp tomato paste, 1 tsp fresh thyme leaves, 1 bay leaf
Cook the beef 2-3 hours, stirring occasionally, until the meat is fork-tender.
While the beef cooks, prepare the onions & mushrooms. Heat 2 tbsp butter in a medium saucepan over medium-low heat. Add the thawed pearl onions and season with kosher salt and freshly ground black pepper. Cook until the onions are lightly browned on all sides, 8-10 minutes. Add the remaining 2 tbsp butter, sliced cremini mushrooms and the remaining minced garlic to the pan. Cook until golden brown, about 6-8 minutes. Season to taste with kosher salt and freshly ground black pepper, if needed. Set aside until beef is ready.
4 tbsp unsalted butter, 1 lb. frozen pearl onions, 1 lb. fresh cremini mushrooms
When the beef is cooked through and tender, transfer the stew from the oven to the stovetop. Remove the lid and set the burner to medium heat. Add the pearl onion/mushroom mixture and bring the stew to a boil (stovetop). Reduce the temperature to low and simmer 15 minutes. Remove the stew from the heat and let sit another 15 minutes.
Discard the bay leaf.
Season the stew to taste, and serve over mashed potatoes or egg noodles.