01 - Preheat oven to 425°F. Line a large baking sheet with parchment paper.
02 - Remove leaves from cauliflower heads and trim stems while keeping cores intact. Slice each head into 1-inch-thick steaks, yielding approximately 2-3 steaks per head. Reserve smaller florets for alternative use.
03 - Arrange cauliflower steaks on prepared baking sheet. Brush both sides with olive oil. In a small bowl, combine cumin, smoked paprika, garlic powder, salt, and pepper. Distribute spice mixture evenly over both sides of steaks.
04 - Roast for 25-30 minutes, flipping halfway through, until golden brown and fork-tender.
05 - While cauliflower roasts, whisk together tahini, lemon juice, water, minced garlic, maple syrup, and salt in a mixing bowl. Adjust consistency by adding additional water in 1-teaspoon increments until achieving creamy, pourable texture.
06 - Arrange roasted cauliflower steaks on serving platter. Drizzle generously with tahini dressing. Garnish with fresh parsley, toasted nuts if desired, and lemon wedges.