Start by peeling and grating the medium cucumber using a box grater. Place the grated cucumber in a fine-mesh sieve positioned over a bowl and press firmly to remove excess moisture. Let it sit for about 5 minutes to ensure most liquid is drained.

In a large mixing bowl, combine the drained cucumber with one cup of Greek yogurt, a handful of chopped fresh dill, two minced garlic cloves, a drizzle of extra-virgin olive oil, and the juice of half a fresh lemon. Stir everything together with a whisk or spatula until creamy.

Cover the bowl with plastic wrap and place it in the fridge for at least one hour to let the flavors meld.

Once chilled, give the tzatziki a gentle stir before serving. Enjoy as a dip for pita bread or fresh veggies, or use as a sauce for grilled meats.