Heat the olive 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 onto a large plate.
Dry the beef cubes with paper towels and then sprinkle them with salt and pepper. In single-layer batches, sear the beef in the hot oil for 3 to 5 minutes, turning them over 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.
Toss the carrots, onions, 1 tablespoon of salt, and 2 teaspoons of pepper into the fat in the pan 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 Cognac, stand back, and ignite with a match to burn off the alcohol.
Put the meat and bacon back into the pot with the juices. Add the bottle of wine plus enough beef broth to almost cover the meat. Add the tomato paste and thyme. Bring to a simmer
Cover the pot with a tight-fitting lid and place it in the oven for about 1 hours 15 minutes or until the meat and vegetables are very tender when pierced with a fork.
Combine 2 tablespoons of butter and the flour with a fork and stir into the stew. Add the frozen onions.
Sauté 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 to taste, serve over toasted bread, and accept compliments graciously.