Bring a large pot of salted water
to a boil. Cook noodles until tender; drain and return to pot. Stir in butter; cover and set aside.
Meanwhile, in a medium bowl, combine
pork with 1 tablespoon paprika; season with salt and pepper, and toss to coat. In a large skillet, heat 1 tablespoon oil over medium-high; cook pork, tossing occasionally, until lightly browned on all sides, 3 to 5 minutes. Transfer to a plate (reserve skillet).
Return skillet to stove; reduce heat to medium. Add remaining tablespoon oil and onion; cook until onion is soft, 4 to 5 minutes. Add pork, remaining tablespoon paprika, tomatoes with their juice, and 1/2 cup water; bring to a boil. Reduce to a simmer; cook, until sauce is slightly thickened, breaking up tomatoes with a spoon, 2 to 4 minutes.
Remove skillet from heat, and stir
in sour cream; season with salt and pepper. Serve paprikash over noodles, garnished with parsley, if desired.
This creamy stew usually takes hours to cook. Here, thanks to swiftly sauteed pieces of pork tenderloin, it's on the table in less than a half hour.