Tzatziki Sauce

Spoon yogurt into sieve lined with cheesecloth or coffee filter set over bowl; cover and refrigerate overnight.

Transfer drained yogurt to medium bowl and discard liquid.

Meanwhile, in colander set over bowl, toss chopped cucumber with 1 teaspoon salt.

Let drain at least 1 hour at room temperature, or cover and refrigerate up to 8 hours.

In batches, wrap chopped cucumber in kitchen towel and squeeze to remove as much liquid as possible.

Pat dry with paper towels, then add to bowl with yogurt.

With flat side of chef's knife, mash garlic to a paste with remaining 1/2 teaspoon salt.

Add garlic, chopped mint, oil, vinegar, and pepper to yogurt and stir to combine.

Cover and refrigerate at least 2 or up to 4 hours.

Serve chilled or at room temperature, topped with cucumber slices and mint sprigs.