Trim fat from steak. Cut beef into 1-inch pieces and then cut each in half.
In large skillet or Dutch oven, heat oil over medium-high heat until hot. Add beef, half at a time, and stir-fry 1 1/2 to 2 minutes or until outside surface is no longer pink. Remove from skillet with slotted spoon; set aside.
In same skillet, add onions, sauerkraut, paprika and 1/4 cup water. Cook and stir until onions are tender, about 3 minutes.
Stir in broth, 1/2 cup water, tomato paste, caraway seed, red pepper and noodles, stirring to separate noodles. Bring to a boil; reduce heat to medium. Cover tightly and simmer 10 minutes or until noodles are tender.
Remove from heat; return beef to skillet. Cover and let stand 1 minute. Sprinkle with parsley; serve with sour cream.