Step 1

Preheat grill to medium-high heat and lightly oil the grate.

Step 2

Whisk oil, lemon juice, garlic, salt, smoked paprika, brown sugar, chili powder, and black pepper together in a bowl. Set aside.

Step 3

Remove the tough bottom leaves from each cauliflower, taking care not to remove the stem. Place the cauliflower heads onto a cutting board with the stem side facing upwards; cut vertically on both sides of the stem to remove the loose florets. Reserve florets for another use.

Step 4

Cut each cauliflower vertically through the stem into 2 even "steaks", 1 to 1 1/2 inches thick. Remove any remaining small leaves from each steak. Place the 4 steaks on a baking sheet.

Step 5

Brush one side of the steaks with some of the oil mixture. Place steaks on the grill, oiled side down; grill for 5 minutes. Brush more oil mixture on top of the steaks and gently flip over; grill until golden brown and slightly charred, 5 to 7 minutes more. Drizzle with any remaining oil and remove to a plate. Sprinkle with cilantro.