In a large skillet over medium heat, saute the meat and onions for 10 minutes, or until the meat is browned and the onion is tender. Stir in the flour, salt and paprika. Then add the mushroom soup, mix well and cook, uncovered, for 20 minutes.
Reduce heat to low and add the sour cream, stirring well and allowing to heat through. Cover and set this mixture aside.
Cook the egg noodles according to package directions. Drain the water from the noodles and pour the meat mixture over the noodles.