Heat a large skillet over medium-high heat. Add bacon. Cook bacon, stirring occasionally, until crisp. Remove bacon, using a slotted spoon, to a paper towel lined plate. Cover and refrigerate for later.
Discard all but about 1 tbsp of the bacon grease. Return pan to burner over medium-high heat. Add beef cubes in batches, making sure they do not touch. Season lightly with salt and pepper. Brown each side of the beef cubes. Do not cook meat throughout. When outside is brown, transfer beef to the slow-cooker crock using a slotted spoon. Repeat for the rest of the meat.
Once all of the beef has been browned and is in the slow-cooker, turn the skillet heat to medium low. Add vinegar to the skillet. Stir, scraping up brown bits, until vinegar has thickened. Pour in about 1/4 cup of the beef broth and continue to scrape up any browned bits. Transfer liquid to the slow-cooker.
Add remaining broth, onion, green beans, celeriac (or celery), carrots, tomato paste, diced tomatoes, garlic, rosemary, thyme, salt, and pepper to the slow-cooker. Stir gently.
Cover the slow-cooker and cook on the low setting for 6-8 hours. Taste and adjust seasoning before serving. Garnish with reserved bacon bits before serving.