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

Transfer the blanched cauliflower to a bowl filled with ice water for 2-3 minutes to cool.

Drain the cauliflower and pat dry with a kitchen towel.

Combine the drained cauliflower, halved cherry tomatoes, sliced red onion, black and green olives, and chopped parsley in a large mixing bowl.

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

Pour the dressing over the mixed vegetables and toss to coat evenly.

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

Give the salad a final toss, adjust seasoning as needed, and serve.