Peel the cucumber, then cut it into very thin slices.

Put the sliced cucumber in a colander, sprinkle lightly with salt and leave it to drain for 20 minutes.

Dry the sliced cucumber with kitchen paper.

Generously butter each slice of bread.

Arrange the cucumber on half the slices, overlapping each slice, and top with the remaining slices of bread.

Pressing down, cut the crusts off, and then cut into triangles (or fingers).

Serve immediately with tea.