Prep the Ingredients: Lay out the rye bread on a clean surface. Spread Thousand Island dressing evenly on one side of each slice. Keep everything close since the cooking goes quickly.
Heat the Pan: Place a skillet over medium heat. Add a small amount of butter and let it melt slowly, coating the surface.
Build the Sandwich Base: Place two slices of bread in the pan with the dressing side facing up. Add a layer of Swiss cheese on each slice.
Add the Filling: Pile corned beef evenly over the cheese. Spoon sauerkraut across the meat and spread it gently so each bite gets some tang.
Finish the Stack: Add another layer of Swiss cheese on top of the sauerkraut. Place the remaining bread slices on top with the dressing side facing down.
Grill Until Golden: Butter the top slices of bread. Cook until the bottom turns golden and crisp. Flip carefully and cook the second side until the cheese melts fully.
Rest and Slice: Remove the sandwiches from the pan. Let them rest for a minute, then slice in half and serve warm.
