Heat the oven to 475°F with a rack in the middle position. Line a broiler-safe rimmed baking sheet with foil and lightly brush the foil with oil. Place the cauliflower in the center, then draw up the edges of the foil; drizzle 2 tablespoons water onto the cauliflower, then enclose the head, folding and crimping the edges of the foil to seal. Bake until a skewer inserted into the cauliflower meets no resistance, 40 to 50 minutes.

While the cauliflower cools, in a 10-inch skillet over medium-low, cook the oil, pepper flakes and garlic, stirring, until the mixture sizzles lightly, 2 to 3 minutes. Transfer to a small bowl, stir in ½ teaspoon salt and set aside. Grate the tomatoes on the large holes of a box grater set in a medium bowl, pressing the cut sides against the grater, until only the skin remains; discard the skins. Stir ¼ teaspoon salt into the tomato pulp and set aside. In a small bowl stir together the tahini and lemon juice. Then stir in 2 tablespoons water, adding more as necessary 1 tablespoon at a time until the mixture is a smooth, spreadable paste. Stir in the cumin, sumac, cardamom, cinnamon and ¼ teaspoon each salt and black pepper; set aside.

Heat the broiler. Spread the tahini mixture onto the entire surface of the cauliflower, then broil until deeply browned, 3 to 4 minutes. Transfer to a serving platter and cool for about 5 minutes. Spoon the tomato pulp over the top, drizzle with the chili-garlic oil and sprinkle with the parsley and pine nuts. Serve with lemon wedges.