Set oven rack about 6" from the heat source and heat the oven's
broiler.
Spread mayonnaise onto 1 side of each bread slice. Layer Swiss
cheese, turkey, and spinach onto the mayonnaise-side of 1 bread
slice; top with second bread slice. Place sandwich on a baking
sheet.
Broil until heated through and cheese is bubbling, about 5 minutes,
turning sandwich over about half way.
