Preheat the oven to 425°F (220°C) and position racks in the upper and lower thirds.

Drain and rinse the canned chickpeas, then dry them thoroughly with a clean towel.

Cut the cauliflower into bite-size florets and smash the 4 garlic cloves.

Toss the chickpeas with 2 tablespoons olive oil, 1/2 teaspoon salt, and 1/4 teaspoon black pepper.

Spread the seasoned chickpeas in a single layer on 1 sheet pan.

Toss the cauliflower and garlic with the remaining 2 tablespoons olive oil, 1 teaspoon salt, and 1/4 teaspoon black pepper.

Spread the cauliflower and garlic in a single layer on the second sheet pan.

Roast both pans for 20 minutes, swapping their rack positions halfway through.

Pit and tear the 6 Medjool dates into small pieces.

Scatter the torn Medjool dates over the roasting pans, then roast for 10 minutes until the vegetables brown and the dates caramelize.

Whisk the tahini, water, lemon juice, ground cumin, and a pinch of salt until smooth and creamy.

Divide the roasted cauliflower, chickpeas, garlic, and dates among 4 servings, then drizzle with the spiced tahini sauce.