Bring a large pot of salted water to a boil and blanch cauliflower florets for 1-2 minutes until slightly softened. Transfer to an ice bath.

Drain the cauliflower in a colander and gently pat dry with a kitchen towel.

In a mixing bowl, combine the blanched cauliflower, cherry tomatoes, red onion, olives, and parsley. Mix gently.

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

Drizzle the dressing over the salad mixture and toss gently to coat.

Cover and marinate in the refrigerator for at least 30 minutes, up to 4 hours.

Before serving, give the salad a gentle toss and adjust seasoning as necessary.