In a medium bowl, stir together ham, egg, celery, mayonnaise, mustard, pickle, and curry powder until well combined. Divide ham salad among 3 bread slices and cover with remaining 3 bread slices to make 3 whole sandwiches.
Using a serrated bread knife in a gentle sawing motion, trim and discard crusts from sandwiches. Cut each sandwich in half to make 6 rectangular sandwiches. Serve immediately, or cover with damp paper towels, place in a covered container, and refrigerate until serving time.
Just before serving, garnish with celery leaves, if desired.
Notes
MAKE-AHEAD TIP: Ham salad can be prepared up to 2 days in advance, placed in an airtight container, and refrigerated until needed.
Recipe by TeaTime Magazine at https://teatimemagazine.com/curried-ham-salad-tea-sandwiches/