Bring a large pot of salted water to a boil. Cook rotini according to package directions until al dente. Drain and rinse under cold water to stop cooking; shake off excess water.

While pasta cooks, halve cherry tomatoes, dice cucumber and bell pepper, thinly slice red onion, and halve olives. Set aside.

In a small bowl or jar, whisk together olive oil, red wine vinegar, Dijon, minced garlic, oregano, salt, and pepper until emulsified.

In a large mixing bowl, combine drained pasta, prepared vegetables, olives, and half of the feta. Pour dressing over top and toss gently until everything is well coated.

Cover and refrigerate for at least 30 minutes (or up to overnight). Just before serving, fold in fresh basil, parsley, and remaining feta. Adjust seasoning if needed.