Preheat your grill to medium-high heat.
Remove any outer leaves from the cauliflower and trim the stem, making sure to keep the core intact.
Slice the cauliflower into 1-inch thick steaks, cutting from top to bottom. You should get 2 large steaks from the center of the cauliflower and possibly a few smaller ones from the sides.
In a small bowl, mix together the olive oil, minced garlic, smoked paprika, cumin, chili powder, salt, and black pepper.
Brush both sides of the cauliflower steaks with the olive oil mixture, making sure they are well coated.
Place the cauliflower steaks on the preheated grill. Cook for about 5-7 minutes on each side, or until they are tender and have nice grill marks.
Once the cauliflower steaks are cooked through, remove them from the grill and transfer to a serving plate.
Garnish with freshly chopped parsley or cilantro.
Serve the grilled cauliflower steaks hot, with lemon wedges on the side for squeezing over the top if desired.