Preheat oven to 550°F with oven rack in center of oven.
Trim stem of cauliflower, keeping leaves intact, so it will sit level on a sheet pan.
Bring 2 gallons of water to a boil in a large pot over high heat. Stir in salt until dissolved.
Add the cauliflower, placing something over the cauliflower to keep it submerged.
Boil until very tender, about 12 to 13 minutes.
Carefully lift the cauliflower from the water and drain. Transfer to the sheet pan, stem side down.
Use a brush and brush the cauliflower with olive oil all over. Sprinkle remaining sea salt and bake in the preheated oven until browned, about 25 to 35 minutes.
Broil for 2 minutes.
Serve hot.
