Bring a large pot of salted water to a rolling boil. Add the cauliflower florets and blanch for 1-2 minutes until bright white but still crisp.

Transfer the florets to an ice bath to halt cooking and preserve crunch and color. Let cool for 5 minutes.

Drain the cauliflower in a colander to remove excess water. Gently pat dry with a towel.

In a large mixing bowl, combine the blanched cauliflower, halved cherry tomatoes, sliced red onions, black olives, green olives, and chopped parsley.

In a separate bowl, whisk together olive oil, red wine vinegar, Dijon mustard, minced garlic, oregano, basil, salt, and black pepper until emulsified.

Pour the dressing over the vegetable mixture and toss gently until each piece is coated.

Cover the bowl and refrigerate for at least 30 minutes to allow the salad to marinate.

Remove from refrigerator, toss gently, adjust seasoning if needed, and serve chilled or at room temperature.