Cook the rotini pasta in a large pot of salted boiling water until al dente, about 8-10 minutes. Drain and rinse under cold water.

Slice cucumber in half lengthwise, scoop out seeds, then chop into bite-sized pieces. Add to a large mixing bowl.

Dice red onion and green peppers, adding them to the bowl with cucumber.

Sprinkle fresh parsley and crumble feta cheese into the vegetable mix. Toss gently to combine.

In a separate bowl, whisk together lemon juice, olive oil, white vinegar, onion powder, garlic powder, salt, and pepper.

Combine the cooled pasta with the vegetable mix and dressing, stirring gently.

Cover and refrigerate for at least 2 hours before serving to allow flavors to meld.