Reuben Sandwich(With Leftover Corned Beef, Make Reubens.)

In a small bowl, mix mustard, mayonnaise and horseradish (if desired).

Place 6 slices of rye bread on a tray.

Make sandwiches by placing 3 slices of corned beef, 1 slice of Swiss cheese and 1 tablespoon sauerkraut on each slice of bread.

With a knife, spread some of the mayonnaise mixture on a slice of rye bread and place on top, completing the sandwich.

Butter both sides of sandwich and lightly grill until Swiss cheese has melted.

Serve hot.