Prepare the ice bath by filling a large bowl with ice and cold water. Bring a large pot of water to a rolling boil.

Add cauliflower florets to boiling water and blanch for 1-2 minutes. Remove and transfer to ice bath.

Let the cauliflower sit in the ice bath for about 2 minutes, then drain and pat dry with paper towels.

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

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

Pour the dressing over the salad mixture and gently toss to combine.

Cover the salad and refrigerate for at least 30 minutes and up to 4 hours for flavors to develop.

Before serving, give the salad a gentle toss, taste, and adjust seasoning with salt and pepper as needed.