Peel the cucumber and slice it into 1/2-inch half-moons. Halve the tomatoes lengthwise. Dice the bell pepper and mince the red onion finely. Coarsely chop fresh parsley and crumble the feta cheese.

Bring salted water to a rolling boil in a large pot. Add the rotini and cook for 8–10 minutes until al dente. Drain and rinse under cold water.

In a medium bowl, whisk together red wine vinegar, olive oil, garlic powder, oregano, salt, and pepper until well combined.

In a large bowl, combine the cooled rotini, prepared vegetables, and crumbled feta. Pour the dressing over and gently toss.

Cover the salad and refrigerate for at least 2 hours to allow flavors to meld.