Whisk oil, vinegar, oregano, salt and pepper in a large bowl.
Using a spiral vegetable slicer with the chipper blade attachment (for thick noodles), cut cucumber lengthwise into "noodles." Cut the noodles into 2-inch lengths.
Add the cucumber noodles, tomatoes, onion, cheese and olives to the bowl and toss to coat with the dressing. Serve topped with more oregano, if desired.
Equipment: Spiral vegetable slicer with chipper blade attachment
2 fat, 1 vegetable, 1/2 high-fat protein