Using a large bowl, add all ingredients except for cucumber, and mix.
Grate cucumber lengthwise into the large bowl (recommended to use the thickest grate possible). Grating lengthwise will add texture of a cucumber crunch in the creaminess of the tzatziki. Fold everything until well mixed.
Add additional salt if needed to lift the flavours (different yoghurts will yield a different salt content).
Place the colander into a bowl that sits so liquid can drain into it.
Line colander with chux or muslin cloth so that some of it overlaps the edges of the colander. Place colander into a larger bowl to catch drained liquid.
Pour mixture into the centre of colander on top of cloth and fill. Fold over cloth edges towards centre to make a bundle.
Place a weight on top of cloth covered Tzatziki mix. Allow to sit for at least 5 hours in the fridge.
Serve with some toast, warm sour dough or pita bread drizzled in olive oil and sea salt.