Slice the English cucumbers into small, bite-sized pieces. Sprinkle with salt and let them sit in a colander for about 15 minutes to drain excess moisture.

In a medium bowl, combine Greek yogurt, crumbled feta cheese, chopped herbs, lemon zest, lemon juice, and black pepper. Mix until smooth and creamy.

Gently fold the drained cucumbers into the yogurt-feta mixture until well-coated.

Prepare your bread by lightly toasting it. Layer sprouts on one slice, then spoon a generous cucumber salad portion on top, followed by red onion slices. Top with another slice of bread.

Slice the sandwiches in half and serve immediately.