Bring a large pot of heavily salted water to a rolling boil. Cook the pasta according to package directions for al dente. Drain immediately and rinse briefly under cold water to stop the cooking process. Set aside in a large bowl to cool completely.

While the pasta cooks, prepare the vegetables. Wash and dry the cucumber and tomatoes. Slice the cucumber into quarter-inch thick half-moons, halve the tomatoes, and thinly slice the red onion. For extra crisp cucumbers, toss the slices with a pinch of salt and let them sit in a colander for 15-20 minutes to draw out excess water, then pat dry.

In a small bowl or a jar with a lid, combine the extra virgin olive oil, red wine vinegar, minced garlic, dried oregano, salt, and black pepper. Whisk or shake vigorously until the dressing is well-emulsified.

In the large bowl with the cooled pasta, add the prepared cucumber, tomatoes, and red onion. Pour about two-thirds of the vinaigrette over the salad and toss gently to combine.

Add the crumbled feta cheese and toss again very gently. For the best flavor, cover and refrigerate for at least 30 minutes to allow the flavors to meld.

Before serving, give the salad a final toss. If it seems dry, add the remaining dressing and adjust seasoning with salt and pepper as needed.