Cauliflower's round shape can be cut into slabs or florets for the grill. Here, it's grilled both ways after being rubbed with a blend of spicy seasonings and basted with a fresh cilantro-lime vinaigrette.
Preheat grill to medium-high. Place a grill basket on the grill while it preheats.
Remove the tough outer leaves of cauliflower. Trim stem to create a flat base, keeping the core intact. Stand the cauliflower upright on a cutting board. Holding the cauliflower firmly and starting from the center, use a large chef's knife to cut four 1 1/2-inch-thick slabs, creating 2 large and 2 small steaks. Reserve the loose florets.
Combine garlic, 1 1/2 Tbsp. oil, chile powder, 1/2 tsp. cumin, 1/4 tsp. salt, and 1/4 tsp. pepper in a small bowl. Rub evenly over the cauliflower steaks and florets.
Whisk lime zest, lime juice, cilantro, honey, and the remaining 2 Tbsp. oil, 1/2 tsp. cumin, 1/4 tsp. salt, and 1/4 tsp. pepper in a small bowl. Spoon 2 Tbsp. of the cilantro mixture into a separate small bowl for basting; reserve the remainder for serving.
Place the cauliflower steaks on the grill and the florets in the grill basket; baste the cauliflower with 1 Tbsp. of the cilantro mixture. Grill until well marked and charred in some spots, 7 to 8 minutes. Flip the steaks and florets and baste with 1 Tbsp. cilantro mixture. Grill until the other side is tender and well marked and charred in some spots, 7 to 8 minutes more.
Transfer to a platter to serve. Drizzle the remaining sauce over the grilled cauliflower.
Equipment: Charcoal or gas grill; grill basket