Heat oil in a large heavy skillet over high heat. Sprinkle 1/4 teaspoon salt and 1/8 teaspoon pepper over pork, tossing to coat. Add pork to pan; cook 4 minutes or until browned, stirring occasionally. Remove pork from pan. Reduce heat to medium-high. Add onion to pan; cook 2 minutes, stirring frequently. Add mushrooms; cook 6 minutes or until mushrooms release moisture, stirring occasionally. Add wine; simmer until wine is reduced by half (about 7 minutes). Reduce heat to medium-low.
Combine sour cream and mustard in a small bowl, stirring with a whisk. Stir sour cream mixture into wine mixture; add pork and remaining 1/4 teaspoon salt and 1/8 teaspoon pepper. Cook 3 minutes or until heated; stir in juice. Sprinkle with parsley. Serve over noodles.