For the tzatziki, first take a clean cloth kitchen towel and place it in a colander. Empty the yogurt into it. Remove the cloth from the sieve, twist it together and let the water drip out of the yogurt.
Peel the cucumber and grate very finely, place in a very fine mesh strainer and squeeze well. Crush the garlic cloves, put everything together in a bowl and season the tzatziki with oil, vinegar, salt pepper and dill.