Brown the ground beef in a skillet over medium heat, breaking it up as it cooks. Drain any excess fat and add the beef to the slow cooker.
Add the diced onion, minced garlic, sliced mushrooms, beef broth, Worcestershire sauce, paprika, salt, and black pepper to the slow cooker. Stir to combine.
Cover and cook on low for 6 hours or on high for 3 hours until the mushrooms are tender.
Stir in the softened cream cheese until it melts into the sauce. Then stir in the sour cream.
Cook the egg noodles in a large pot of boiling water according to package directions. Drain them well.
Serve the stroganoff over the cooked egg noodles and sprinkle with chopped fresh parsley.