In a large mixing bowl, combine beef stew meat with Worcestershire sauce, salt, black pepper, dried Italian seasoning, and smoked paprika. Toss everything thoroughly.

Place the halved baby potatoes in the bottom of your slow cooker. Drizzle half of the melted unsalted butter and olive oil over them.

Carefully layer the marinated beef over the seasoned potatoes in the slow cooker. Drizzle the remaining melted butter and olive oil over the beef.

Cover the slow cooker and cook on low for 6 to 7 hours or on high for 3 to 4 hours. Check for doneness when the beef is fork-tender.

Gently stir the beef and potatoes to combine before serving. Garnish with chopped fresh parsley if desired.