Season the beef stew meat with salt and pepper. Heat olive oil in a large skillet over medium-high heat, add the beef cubes and sear for 2-3 minutes on each side until brown. Transfer beef to slow cooker.

In the same skillet, reduce heat to medium, add unsalted butter, and melt. Add minced garlic and sauté for about 1 minute until fragrant. Remove from heat.

Pour beef broth and Worcestershire sauce into the skillet, scraping up the browned bits. Stir in thyme and rosemary. Pour sauce over seared beef in slow cooker.

Halve the baby potatoes and add them to the slow cooker, mixing gently. Cut remaining butter into small pieces and place on top.

Cover slow cooker and cook on low for 6-7 hours or on high for 3-4 hours until beef is tender.

Once cooked, check for seasoning, adjust with more salt and pepper if needed, and garnish with freshly chopped parsley.