Begin by prepping your ingredients. Peel and quarter the potatoes, and dice the onion. Cut the beef stew meat into bite-sized pieces if not already done.
Optional: In a large frying pan over medium-high heat, melt ¼ cup of the butter. Add the beef bites and brown them on all sides for about 5-7 minutes.
In the slow cooker, combine the browned beef (or raw beef if skipping browning), quartered potatoes, diced onion, minced garlic, soy sauce, dried thyme, dried rosemary, salt, and pepper.
Pour the beef broth over the mixture in the slow cooker and add the remaining butter (¼ cup) cut into small pieces on top.
Cover and cook on low for 6 hours or high for 3 hours, until the beef is tender and the potatoes are cooked through.
Once cooking is complete, taste and adjust seasoning if necessary. Serve hot, garnished with chopped fresh parsley.