In a medium bowl, combine all ingredients until incorporated. Season with salt.
Make the Sandwiches
Preheat your oven to 350°F. Lightly brush the butter on each slice of bread and arrange on a sheet pan. Lay a slice of Swiss cheese on each piece of bread and toast in the oven for about 3 minutes, or until the cheese starts to melt.
In a small skillet over medium heat, warm the sauerkraut.
Assemble the sandwiches by adding ½ pound of corn beef and ¼ cup of sauerkraut on each. Close the sandwiches and secure each with a toothpick. Serve with Russian dressing on the side for dipping. Enjoy!