Preheat the oven to 350 degrees F.

Heat oil in a large Dutch oven. Add the bacon and cook over medium heat for 10 minutes, stirring occasionally, until the bacon is lightly browned. Remove the bacon with a slotted spoon to a large plate, and set aside.

Trim off excess fat and dry the beef cubes with paper towels to take away excess moisture. Season beef with salt and pepper, and in batches In single layers, sear the beef in the hot oil for 3 to 5 minutes, turning to brown on all sides. Remove the seared cubes to the plate with the bacon and continue searing until all the beef is browned. Set aside.

After all the beef is seared, add the carrots, and onions to the fat and cook for 10 to 15 minutes, stirring occasionally, until the onions are lightly browned. Add the garlic and cook for 1 more minute. Add the tomato paste and cook tomato paste with vegetables, about 1 minute. Standing at a secure distance, add cognac and slightly lift the side of the pot to ignite into a small flame and burn off the residual alcohol. Place the seared beef, bacon, thyme, the entire bottle of wine plus enough beef broth to almost cover the meat to the pot. Bring to a simmer, cover the pot with a tight-fitting lid and place it in the oven for about 1 1/2 hours or until the meat and vegetables are very tender when pierced with a fork.

Remove stew from the oven once the hour and a half is up. Set on stove, over a low flame. Combine 2 tablespoons of butter and the flour with a fork and stir into the stew. Add the frozen onions. In a skillet over high heat, saute the mushrooms in 2 tablespoons of butter for 10 minutes until lightly browned and then add to the stew. Bring the stew to a boil on top of the stove, then lower the heat and simmer for 15 minutes. Season with salt and pepper to taste