01 - Rub beef cubes evenly with salt, pepper, and dried thyme, coating all surfaces.
02 - Arrange seasoned beef in the slow cooker insert, then top with chopped onion and minced garlic.
03 - Whisk together beef broth, Worcestershire sauce, tomato paste, and flour in a medium bowl until completely smooth and lump-free.
04 - Pour liquid mixture over beef and vegetables. Stir gently to distribute evenly. Cover and cook on low setting for 6-7 hours or on high for 3-4 hours until beef is fork-tender.
05 - Taste gravy and adjust seasoning if necessary. Serve immediately over mashed potatoes, noodles, or rice, garnished with fresh parsley.