Preheat oven to 400°. Place the cauliflower close together on a parchment paper lined baking sheet and toss with 2 tablespoons of the oil and za'atar and bake for 30 minutes. It can be ready to go now with a bit of sea salt, or to make it extra rich and crispy toss in the additional 2 tablespoons of oil and salt and bake for 15 more minutes.
For the sauce, combine all the ingredients in a small bowl and mix until fully blended.
Recipe by Love from the Land at https://www.lovefromtheland.com/roasted-zaatar-cauliflower-tahini-dressing/