Grate a cucumber using the larger holes on your grater. To get rid of as much moisture as possible, place the cucumber onto 2 to 3 layers of paper towels and squeeze well.

In a large bowl, add the yogurt. Slowly whisk in the olive oil until it is well incorporated. Stir in the lemon juice, grated cucumber, garlic, parsley, dill, mint, salt, and pepper. Set dressing aside while you prepare the other ingredients.

Finely chop the onion and add it to a small fine mesh strainer.  Rinse under very hot water for 45 seconds. Repeat with cold water. This will help to take the bite out of the raw onion.

Slice your cucumber in half lengthwise and use a spoon to scrape the seeds out.  Cut the cucumber into ¼ to ½-inch pieces.

Add chicken, cucumber, olives, red onion, and crumbled feta to the bowl with the dressing. Using a rubber spatula, stir to combine until the mixture is fully coated in the sauce.

Before serving, garnish with additional crumbled feta and a sprinkle of chopped fresh herbs, if desired. Serve as is, with crackers or veggies for dipping, or on sliced bread to make a sandwich.