Preheat your grill or stove to medium heat. If you have a grill with a flat top or griddle surface, that's ideal. Otherwise, you can use a grill pan or simply a skillet on a stove!
Prepare the Corned Beef:
If your corned beef is cold, you can gently warm it on the grill/in pan. Just warm it enough to be hot, do not over cook it.
Toast the Bread:
Lightly butter or oil the outside of the rye bread slices.
Place the bread on the grill and toast until golden brown and slightly crispy.
Assemble the Sandwich:
Spread your chosen sauce on both slices of toasted bread.
Layer on the Swiss cheese and corned beef
Place the top slice of bread on the sandwich.
Grill the Sandwich (Optional):
If you want a warm, melted cheese sandwich, you can carefully place the assembled sandwich back on the grill for a minute or two on each side.
If you do this, watch it carefully, so that the bread does not burn.
Serve:
Cut the sandwich in half and serve immediately with a side of pickles or chips.