Gather all ingredients and equipment.
Butter one side of each slice of rye bread.
Lay out four slices of bread, buttered side down, on a clean surface.
Layer the corned beef on each slice of bread.
Add a spoonful of sauerkraut on top of the corned beef.
Place a slice of Swiss cheese on top of the sauerkraut.
Spread dressing on the remaining slices of bread and place them on top, buttered side up.
Preheat the skillet or griddle over medium heat.
Carefully transfer the sandwiches to the skillet, cooking for 4-5 minutes until golden brown.
Flip the sandwiches and cook for another 4-5 minutes, until the cheese has melted and both sides are golden.
Remove the sandwiches from the skillet and let them cool briefly before slicing in half.
Serve immediately with additional dressing, if desired.