Begin by dicing the English cucumbers into small, even pieces. Place them in a colander and sprinkle lightly with salt, allowing them to drain for about 15 minutes.

In a large mixing bowl, combine the plain yogurt, crumbled feta cheese, finely chopped fresh herbs, lemon zest, lemon juice, and a touch of black pepper. Stir until smooth.

After draining, pat the cucumbers dry with a clean paper towel. Add them to the yogurt and feta mixture, folding them in until well coated.

To assemble, place a slice of sturdy bread down, spread the cucumber mixture over it, add sprouts and onion slices, then top with another slice of bread.

Cut the sandwiches in half diagonally and serve immediately.