Lightly butter one side of each of the bread slices.
Spread Thousand Island dressing on one side of one slice of bread.
Place the slice of bread with the buttered side on the bottom.
Layer the ingredients in the following order: one slice of Swiss, corned beef, sauerkraut, and the other slice of Swiss. Top with the second slice of bread with the dressing inside the sandwich.
Grill the sandwich until each side is a pleasing golden brown. Serve hot.