Heat the olive oil in the Dutch oven over medium heat. Once the oil is hot, add the bacon slices. Cook the bacon until crispy, about 3 to 4 minutes. Remove from the Dutch oven with a slotted spoon and transfer to a paper-towel-lined plate. Set aside.
Drain all but one tablespoon of bacon grease and oil from the Dutch oven. Add the beef and brown on all sides, about 5 to 6 minutes. Once the meat is evenly browned on all sides, remove and transfer to a separate plate.
If there is more than one tablespoon of excess liquid in the pot, drain all but one tablespoon, then add half the onions, and all of the garlic and carrots. Sauté for 2 to 3 minutes, just until the vegetables have softened slightly.
Add the beef back to the pot. Sprinkle the flour over the beef and stir with a wooden spoon to coat the beef. Add the remaining onions.
Pour in the red wine and beef broth. Add the tomato paste, thyme, mushrooms, and bay leaves.
Cover and cook on low for 2 to 2½ hours.
Once the beef bourguignon is cooked, return the bacon to the pot, season with salt and pepper, stir, and serve.
Notes
Makes approximately 6 servings.STORAGE: store leftovers in an airtight container in the refrigerator for up to 4 days or in the freezer for up to two months.