Boil a pot of salted water. Cook the pasta according to the instructionson the package, but cook for 2 minutes less to achieve an al dente texture.Drain the pasta well.
To prepare the dressing, blend together olive oil, lemon juice, dijon mustard, garlic, oregano, and salt. For a smoother dressing, you can also use a small food processor.
Chop all the ingredients for the salad.
In a spacious bowl, gently mix the pasta and dressing together. Next, include the tomatoes, cucumbers, onions, olives, and feta cheese. Toss the ingredients well. This dish can be enjoyed either cold or at room temperature.