Start your Spark and set to 500°F; brush the grill grates with oil. While the grill preheats, prep the cauliflower: Bring a large pot of salted water to a boil. Carefully submerge the whole cauliflower head in the water and par-cook for about 5 minutes. Remove from the water and drain thoroughly.
Grill the cauliflower and lemon: Slice the cauliflower head into
1-inch-thick steaks or quarter it. Brush each side with olive oil. Place the cauliflower on the grill along with the lemon halves, cut side down. Grill the cauliflower for about 20 minutes, turning halfway through. Grill the lemons until caramelized, about
Mix the tahini and turmeric in a bowl. Wash the parsley and remove the stems.
Remove the cauliflower and lemons from the grill. Transfer the cauliflower to a platter and top with the parsley and pomegranate seeds. Drizzle with the tahini dressing and the juice from 1/2 of the grilled lemon. Serve with extra grilled lemon and pomegranate wedges if desired.