How to Make It
Preheat oven to 450°F with racks in upper and lower thirds. Place 2 rimmed baking sheets in oven while it preheats.
Combine kale, lemon zest, 1 tablespoon of the lemon juice, 1 tablespoon of the oil, and ¼ teaspoon each salt and pepper in a large bowl. Toss to coat and massage into kale leaves.
Slice cauliflower vertically, creating some large steaks and small florets as you cut through the stalk. Remove one of the hot baking sheets from the oven and place cauliflower in a single layer on baking sheet. Drizzle with 2 tablespoons of the oil, ¾ teaspoon salt, and ½ teaspoon pepper. Turn to coat and return to oven.
Toss chickpeas with 1 tablespoon of the oil and ¼ teaspoon each salt and pepper in a medium bowl. Place in an even layer on second hot baking sheet and return to oven. Roast cauliflower and chickpeas, flipping cauliflower halfway through and rotating baking sheets top to bottom, until cauliflower is browned and chickpeas are crispy, 20 to 25 minutes.
Whisk together tahini, water, remaining 4 tablespoons lemon juice, 2 tablespoons olive oil, and ¼ teaspoon each salt and pepper in a medium bowl. Spoon dressing onto 4 plates. Top with cauliflower, kale, and chickpeas. Serve with lemon wedges.