Ingredients:
1/4 cup brown mustard
8 slices rye bread
1 pound corned beef, sliced
4 slices Swiss cheese
1 cup sauerkraut, drained
1/2 cup sour cream
1/4 cup butter, melted

Directions:
Spread mustard on one side of 4 slices of bread. Arrange corned beef, cheese and sauerkraut evenly over each slice.
Spread sour cream over remaining bread slices; place over sauerkraut. Brush butter on one side of each sandwich.
Grill, buttered side down, in medium-hot skillet until golden brown. Brush butter on top slice of sandwiches; turn and grill until golden brown. Serve immediately.