In a stockpot or Dutch oven, melt butter over medium heat. Add the beef, stirring to brown on all sides. Add the onion and cook until soft.
Mix together flour, salt, pepper, paprika and garlic powder, then sprinkle over beef and onions. Stir well to coat. Stir in beef broth, scraping any stuck bits in the pot as needed, then add rosemary. Bring to a boil, then reduce heat to low, cover and let simmer for 25-30 minutes, until beef is tender.
Add carrots, celery and bulgur and continue to simmer, uncovered, for 15-20 minutes, until vegetables are softened and grains have fully absorbed liquid. Remove rosemary sprigs, taste, and adjust salt and pepper as needed.