Slice 1 cucumber lengthwise into strips, should make between 8 and 10 long strips. Cut the strips in half. Cut 1/2 of a cucumber into disks, about 18-20. Wrap one strip half around the cucumber disks to create a cup. Secure strip closed with a toothpick or skewer.
Dice 1/2 of a cucumber, sweet peppers, onion and olives. In a mixing bowl whisk together olive oil, vinegar, oregano, pepper flakes, salt and pepper. Add diced vegetables and 2 ounces of the crumbled feta. Toss to combine. Let stand until ready to serve.
Fill each cucumber cup with a heaping tablespoon of pepper mixture. Sprinkle with remaining crumbled feta. Serve immediately.