01 - Lay out all rye bread slices on a clean surface. Spread mustard evenly on two slices. If using mayonnaise for a creamier variation, spread it on the remaining two slices.
02 - Place Swiss cheese slices directly on the mustard-covered bread. The mustard helps the cheese adhere and adds flavor depth.
03 - Distribute the sliced corned beef evenly over the cheese layer. Pile it generously to ensure substantial portion coverage across both sandwiches.
04 - Arrange dill pickle slices, thinly sliced red onion, and shredded lettuce over the corned beef layer for texture contrast and freshness.
05 - Complete each sandwich by placing the remaining bread slice on top, mayonnaise side down if used. Press gently to compact layers.
06 - Using a sharp bread knife, slice each sandwich diagonally or vertically in half. Serve immediately while bread remains fresh and crisp.