In a large Dutch oven, cook the bacon over medium-high until crisp, 4 minutes. Using a slotted spoon, transfer to a bowl.
Season the beef with salt and pepper and add it to the pot in a single layer. Cook, stirring, until browned all over, about 8 minutes. Transfer to a plate.
Add the mushrooms and cook, stirring occasionally, until browned, about 4 minutes.
Reduce the heat to medium and stir in the cooked meat, carrots, onion, tomato paste and butter. Season and cook, stirring, 1 minute.
Sprinkle with flour and cook, stirring, 2 minutes.
Stir in the stock, wine and 1 tbsp. thyme; bring to a boil.
Reduce the heat to medium-low, cover and simmer until the meat is tender and the sauce thickens, about 1 ½ hours.
Stir in the cooked bacon; season. Divide among bowls, garnish with the remaining thyme and serve with the baguette slices.