Preheat oven to 350℉.

Slice the leftover smoked corned as thin as possible.

Pile the sliced smoked corned beef into two sandwich-sized heaps on a baking sheet.

Top each beef pile with sauerkraut and two slices of Swiss cheese.

Place into the oven and cook until the cheese is melted and gooey.

Put each smoked corned beef pile onto a slice of dark rye and top with another slice of bread that has been smeared with stone-ground mustard.

Melt butter in a non-stick pan.

Grill the Reuben sandwiches until each side a crispy and buttery.

Dig on in!