* You can use prepared hummus, which cuts down on the prep time.
How to make it
Use a rolling pin to flatten each slice of bread.
Using a mandoline or a very sharp knife, slice cucumber into paper-thin rounds, about 1/16 inch thick. Place slices in a medium mixing bowl, and toss with salt. Place cucumber slices in a colander or sieve set over a mixing bowl; let drain for 15 to 20 minutes.
Meanwhile, using a mandoline or a very sharp knife, slice lemon into paper-thin rounds, about 1/16 inch thick, removing any seeds as you go. Set slices aside.
Spread 1 tablespoon of the hummus evenly on one side of each slice of bread.
Lightly blot cucumber slices with paper towels to remove excess moisture. Shingle cucumber slices over hummus on 3 slices of bread—you should use roughly 10 to 12 slices on each sandwich. Top cucumbers with a layer of lemon slices (about 4 slices per sandwich).
Close sandwiches with remaining slices of bread. Trim the edges again. If making tea sandwiches, cut each sandwich into 4 squares, and serve.