Bring a large pot of salted water to a boil and cook the pasta according to package instructions until al dente. Drain and rinse briefly under cool water, then spread on a tray to cool completely.

While the pasta cools, chop the vegetables: slice cherry tomatoes in half, dice cucumber into small chunks, and cut red onion into thin slivers. Place in a large mixing bowl with sliced olives and chopped parsley.

In a small bowl or jar, combine olive oil, red wine vinegar, minced garlic, dried oregano, salt, and black pepper. Whisk until emulsified and slightly creamy. Taste and adjust seasoning if needed.

Add the cooled pasta to the bowl with vegetables. Pour the dressing over the mixture and toss gently until everything is lightly coated.

Fold in the crumbled feta cheese last, mixing gently to avoid breaking it down into a paste.

Cover the bowl and refrigerate for at least 30 minutes to allow flavors to settle. Before serving, toss again and adjust with a drizzle of olive oil if needed. Serve chilled or slightly cool.