Gather and prep all ingredients. Drain the sauerkraut, making sure to squeeze as much liquid out as you can.

Add butter to a pan over medium-low heat. Once melted and hot, add in the corned beef slices and fry for 1-2 minutes on each side, or until slightly crisped.

While the corned beef is cooking, combine the sour cream, mayonnaise, and dijon mustard and mix together well.

Add the drained sauerkraut and spread to distribute evenly across the layer of corned beef.

Dollop the mayo mixture over the top of the sauerkraut.

Layer sliced (or shredded) swiss cheese over the top. Allow cheese to melt, covering if needed.

Spoon out and serve with pickle on the side. Enjoy!