Begin by bringing a large pot of salted water to a rolling boil. Add the cauliflower florets and blanch for 1-2 minutes until bright and slightly tender but still crisp. Transfer to a bowl of ice water.

After cooling for about 3 minutes, thoroughly drain the cauliflower in a colander. Spread on a clean towel or paper towel and pat dry.

In a large mixing bowl, combine the blanched cauliflower with sliced cherry tomatoes, diced red onion, black and green olives, and freshly chopped parsley. Toss until evenly mixed.

In a separate bowl, whisk together the olive oil, red wine vinegar, Dijon mustard, minced garlic, oregano, basil, salt, and black pepper until well blended. Add red pepper flakes if desired.

Pour the dressing over the vegetable mixture. Toss gently until everything is coated in dressing.

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

Before serving, give the salad one last gentle toss and adjust seasoning with salt and pepper. Transfer to a serving dish.