Place the beef stew meat, sliced mushrooms, chopped onion, and minced garlic in the slow cooker.
Add the beef broth, Worcestershire sauce, paprika, salt, and black pepper. Stir to combine.
Cover and cook on low for 7 hours.
In a small bowl, whisk the flour with 1/4 cup of the cooking liquid from the slow cooker until smooth. Stir the mixture back into the slow cooker.
Stir in the sour cream until the sauce is evenly creamy.
Cook the egg noodles according to package directions in a separate pot. Drain well.
Serve the stroganoff over the hot egg noodles and sprinkle with chopped parsley.