This cool, creamy yogurt condiment can be used as a dip for crudite, or in place of sour cream as a topping for cold soups, such as borscht.
Toss cucumber with salt in a colander, and let drain for 20 minutes. Press lightly to extract excess water, then transfer cucumber to a medium bowl. Stir in yogurt, garlic, lemon juice, and dill. Cover, and refrigerate for 1 hour (or up to 1 day).
Make the tzatziki up to a week before you use it.