Spoon the yogurt into a sieve placed over a bowl and place in the refrigerator to drain for 4 hours.
Peel and seed the cucumber(s). If using the large cucumber, grate it; if using the small cucumbers, cut into tiny dice. Place the grated or diced cucumber in a colander and sprinkle with salt. Allow to drain for 30 minutes, then squeeze dry in a kitchen towel. Refrigerate until needed.</