Season the beef generously with salt and pepper. Heat the butter and oil in a large skillet over medium-high heat. Cook the beef, in batches, until nicely browned on all sides, then transfer to a bowl. Drain the excess fat from the skillet. Add the wine to the skillet and bring to a simmer, and then turn the heat off underneath it.
Preheat the oven to 350 degrees F. Set a heatproof pot or Dutch oven over medium-high heat. Add the bacon and cook until crispy. Add the mushrooms, onion and garlic and cook until the mushrooms and onions are tender, about 4 to 5 minutes. Mix in the flour and tomato paste until well-combined. While stirring, slowly mix in the heated wine, and then add the beef to the pot. Bring the mixture to a simmer. Cover and cook the beef Bourguignon in the oven for 90 minutes, or until the beef is very tender. Adjust the seasoning with salt and pepper; garnish each serving with chopped, fresh parsley.