Peel cucumber and cut it in half. Scoop the seeds out with a spoon.
Grate the cucumbers with a box grater. Using a strainer, remove excess liquid from the cucumber pressing down with a spoon. Alternatively, use a muslin cloth or dish cloth to squeeze the excess water out.
In a medium bowl, whisk together Greek yogurt, grated cucumber, chopped dill, minced garlic, lemon juice, olive oil, salt and pepper. Adjust seasoning if needed.
Cover and refrigerate until ready to use. Serve garnished with chopped dill and a drizzle of olive oil.
Notes
Add a tablespoon of sour cream to make Tzatziki creamy.
Store leftover Tzatziki sauce in an airtight container in the fridge for 3 to 4 days.