In a skillet over medium heat, cook the bacon until crisp. Remove bacon and set aside.
Season the beef chunks with salt and pepper. In the same skillet, sear the beef on all sides until browned. Transfer to the slow cooker.
Pour red wine into the skillet, scraping up any browned bits. Add beef broth and tomato paste, stirring until combined. Bring to a simmer. Transfer to the slow cooker.
Add garlic, carrots, potatoes, mushrooms, onion, and the cooked bacon.
Sprinkle flour over the ingredients and stir to combine. Tuck in the thyme sprigs.
Cover and cook on low for 8 hours, or until the beef is tender.
Remove thyme sprigs before serving. Adjust seasoning with salt and pepper if needed.