Cook the pasta according to the package instructions. Drain and rinse under cold water to stop the cooking process. Set aside.

In a small bowl, make the dressing by whisking together olive oil, red wine vinegar, Dijon mustard, garlic, oregano, and some salt and pepper.

In a large bowl, combine the cooked pasta, cherry tomatoes, cucumber, onion, and parsley. Pour the dressing over the top and toss to coat.

If time permits, chill the salad in the refrigerator for at least 30 minutes, covered, to allow the flavors to meld. Serve cold.