1. Preheat oil to 350 degrees.
  2. Gently whisk egg while in a small bowl and set it aside.
  3. Dice corned beef and Swiss cheese and add it to a mixing bowl. Add sauerkraut and mix everything until it’s evenly incorporated throughout.
  4. To roll the egg rolls: place egg roll wrapper on a diamond. Spread about 2 tablespoons of Reuben filling in a line, leaving about an inch on each side. Gently and carefully, fold the corner that’s closest to you over the filling mixture, and tuck under the filling. Fold both side corners toward center of wrapper, it will start to look like an open envelope. Dip your fingers in egg white and run it along the edges of the wrapper to seal better. Carefully roll up the egg roll.
  5. Fry egg rolls in batches until golden brown, turning once the bottom side turns golden.
  6. Serve with Thousand Island dressing for dipping.