Put them in a colander and sprinkle with the tablespoon of salt. Cover with a plate and sit something heavy on top. Let sit for 30 minute. Drain well and wipe dry with a paper towel.
In food processor/blender, add cucumbers, garlic, lemon juice, dill and mint, and a couple dashes of black pepper. Process until well blended, then stir into yogurt. Salt to taste. Place in refrigerator for at least two hours before serving so flavors can blend.
This will keep for a few days in the refrigerator, but you will need to drain off any water and stir each time you use it.
