Brush one side of tortilla with butter and place tortillas, butter side down on skillet.
Top each tortilla with 1/4 cup swiss cheese, 1/4 cup shredded corned beef, 2 tsp sauerkraut and top with 1/4 swiss. Drizzle with thousand island if desired.
Fold in half.
Cook 3-5 min until golden brown and cheese is good and melty.