Add the beef stew meat, sliced mushrooms, zucchini half-moons, diced onion, and minced garlic directly to the slow cooker.
In a small bowl, stir together the beef broth, paprika, Dijon mustard, salt, and black pepper until combined.
Pour the broth mixture over the meat and vegetables in the slow cooker. Stir once to distribute.
Cover and cook on low for 7 hours until the beef is tender.
Stir in the softened cream cheese and sour cream until the sauce becomes smooth. Cover and cook for 20 more minutes.
Sprinkle with chopped parsley before serving.