Toss the beef with 1/2 teaspoon each salt and pepper. Heat the oil in a pressure cooker over medium-high heat. Add the beef and cook, stirring occasionally, until browned on all sides, about 4 minutes. Add the onions and cook, stirring frequently, until the onions soften and begin to brown, about 4 minutes. Add the white wine, mustard and flour, bring to a simmer and cook until reduced by half, about 2 minutes. Add the beef broth, mushrooms, carrots and celery.
Secure the pressure cooker lid and bring to high pressure over medium heat. Once at high pressure, cook for 18 minutes. Remove from the heat and, using the quick-release valve, carefully open. Stir in the neufchatel, parsley and salt and pepper to taste.
Meanwhile, bring a pot of water to a boil and cook the egg noodles according to package directions. Drain and keep warm.
Divide the noodles and beef stroganoff evenly among 6 serving bowls.