Preheat oven to 425°F (220°C).
In a small bowl, combine curry powder, paprika, cumin, salt, and pepper to make the spice blend. Set aside.
Spread cauliflower florets on one large rimmed baking sheet and the dried chickpeas on a separate baking sheet.
Toss cauliflower with 2 tablespoons olive oil and the majority of the spice blend. Toss chickpeas with remaining 1 tablespoon olive oil and 1 tablespoon of the spice blend.
Place both baking sheets in the oven. After 15 minutes, shake the chickpea pan and toss the cauliflower. Remove the chickpeas at the 30-minute mark.
Continue roasting the cauliflower for an additional 5–10 minutes, until the tips are lightly charred. Remove from oven.
While vegetables roast, prepare the Green Tahini Sauce: add all sauce ingredients to a blender or mini food processor. With the motor running, gradually stream in the warm water and blend until completely smooth and creamy. Taste and adjust salt or lemon as needed.
Assemble bowls: divide the cooked rice between 4 bowls. Top evenly with roasted cauliflower and chickpeas. Add cucumber, cherry tomatoes, and fresh cilantro if using. Drizzle generously with Green Tahini Sauce.
Serve immediately and enjoy.