Begin by dicing your firm English cucumbers into small pieces and placing them in a colander. Sprinkle them generously with salt and let them sit for 15 minutes to draw out excess moisture. After 15 minutes, gently pat the cucumbers dry with a paper towel.

In a medium mixing bowl, combine plain yogurt, crumbled feta cheese, finely chopped fresh herbs like dill or chives, lemon zest, and a splash of lemon juice. Season with freshly cracked pepper and mix thoroughly until creamy.

Carefully add the drained, pat-dried cucumbers to the yogurt mixture. Stir gently but thoroughly to ensure even coating of the cucumbers.

Lay out slices of bread, spread the cucumber mixture over one slice, top with sprouts and onion slices, then place a second slice of bread on top.

Using a sharp knife, cut each sandwich in half and serve immediately for best freshness and flavor.