peel and de-seed the cucumber then grate - place the grated cucumber in a tea towel, gather the ends and squeeze to remove the liquid
You can either just stir all the ingredients together (in this case be sure to mince the mint leaves well)
OR place all the ingredients in a food processor and blend - you can blend a little or a lot depending on the texture you want in the end.
refrigerate and let the flavors develop together.
serve with pita bread triangles or on top of gyros
Video
Notes
if you don't have access to greek yogurt you can place plain yogurt in a tea towel, gather then ends and tie to a wooden spoon and hang over a bowl overnight in the fridge - this will thicken the yogurt to the thickness needed