Step 1: Bring a large pot of salted water to a boil and cook the pasta according to package directions until al dente.
Step 2: Drain the pasta and immediately rinse under cold water to stop the cooking process; set aside in a large mixing bowl.
Step 3: In a small jar or bowl, whisk together the olive oil, red wine vinegar, Dijon mustard, oregano, salt, and pepper until emulsified.
Step 4: Add the diced cucumbers, tomatoes, bell peppers, red onion, olives, and cheese to the bowl with the cooled pasta.
Step 5: Pour two-thirds of the dressing over the salad and toss well to ensure everything is evenly coated.
Step 6: Cover and refrigerate for at least 30 minutes. Before serving, toss with the remaining dressing and garnish with fresh parsley.