# Directions:
01 - Arrange bread slices on a clean work surface.
02 - Spread a thin, even layer of mayonnaise on one side of each bread slice.
03 - If using, spread Dijon mustard on the opposite side of two bread slices.
04 - Place two cheese slices between two bread slices with mayonnaise sides facing outward; repeat for second sandwich.
05 - Warm a nonstick skillet over medium-low heat.
06 - Place sandwiches mayo-side down in skillet and cook 3 to 4 minutes until golden brown.
07 - Flip sandwiches and cook 3 to 4 minutes, gently pressing with spatula until bread is golden and cheese melts.
08 - Remove from heat, allow sandwiches to rest for 1 minute, then slice and serve immediately.