Turn sliced beets (roasted yourself or even from a can--I know!) into a Reuben for a pub-style meal anytime. Serve with a kosher dill pickle and dark beer. You'll need to make a batch of Reuben cheese that makes enough for four Reubens.
Preheat a cast iron griddle or skillet over medium low heat while you prepare the sandwiches.
Spread both sides of the bread with about 2 tablespoons of the Reuben cheese. Layer the beets on top of the bottom bread slice and top thickly with sauerkraut and cover with the other bread slice.
Add 2 tablespoon of the butter to the griddle. As soon as it melts, tilt to spread it around and arrange the sandwiches to fit. Cook on the first side until the bread is deeply browned and the cheese begins to melt, about 5 minutes. Flip and cook on the second side until the cheese is completely melted and the sandwich is heated through, about 5 minutes more.