Dice the English cucumber into small, even pieces. Sprinkle a pinch of salt and let it drain in a colander for about 10 minutes.

In a mixing bowl, combine low-fat Greek yogurt, crumbled feta cheese, chopped fresh herbs, lemon juice, lemon peel, and black pepper. Stir until smooth.

After 10 minutes, drain and pat the cucumber dry with a kitchen towel. Fold the cucumber into the yogurt mixture.

On slices of whole-grain bread, layer alfalfa sprouts first, then spread the cucumber-yogurt mixture, top with red onion slices, and cap with another slice of bread.

Cut sandwiches in half diagonally and serve immediately for a refreshing meal.