Recently I traveled to Israel and had a version of this cauliflower dish several times. I shortened the cooking time by sauteing the cauliflower instead of roasting it. You can throw some garlic cloves in at the same time and they get deliciously golden and soft. The sumac in the za'atar spice really brightens up the whole dish.
Heat the olive oil and canola oil in a large nonstick skillet over medium-high heat. Add the garlic and cauliflower and season with salt and pepper. Cook, stirring occasionally, until the cauliflower is tender and golden in spots, about 10 minutes.
Meanwhile, combine the tahini, yogurt, pomegranate molasses, cumin, cayenne, lemon juice, 1 teaspoon salt and a few grinds of pepper in a small bowl.
Transfer the cauliflower and garlic to a medium bowl and set aside. Wipe out the skillet and set over low heat.
Add the tahini mixture and 1/3 cup water to the skillet and cook, stirring frequently, until smooth and warm, about 3 minutes. Add the cauliflower and garlic and toss to combine. Season with salt and pepper. Transfer to a serving platter.
Combine the sesame seeds and za'atar in a small bowl. Top the cauliflower with the chopped parsley and sesame seed mixture.