If necessary, cut beef roast into 2 or 3 large pieces. Place beef in 3 1/2 to 4-quart slow cooker. Top with onion.
In measuring cup, combine broth, chili sauce, paprika, garlic-pepper blend, salt and caraway seed; mix well. Pour over beef and onion.
Cover; cook on low setting for 7 to 8 hours.
About 20 minutes before serving, cook egg noodles to desired doneness as directed on package. Remove beef from slow cooker; cover to keep warm. Stir sour cream into liquid in slow cooker until blended. Increase heat setting to high; cover and cook an additional 5 minutes or until of desired consistency.
Drain noodles. Cut beef across grain into slices. Serve beef with sauce mixture over noodles. Garnish each serving with tablespoon of sour cream; sprinkle with parsley.