Preheat your oven to 400°F (200°C). Arrange broccoli, Brussels sprouts, and sweet potato on a baking sheet. Drizzle with olive oil, sprinkle garlic powder, salt, and pepper, then toss to coat evenly.
Place the baking sheet in the oven and roast for 20-25 minutes, turning halfway through. The veggies should be tender with slightly caramelized edges for that perfect roasted flavor.
While veggies roast, toss drained chickpeas with olive oil, salt, pepper, and garlic powder. Spread them on a separate baking sheet and roast for 15 minutes until golden and crisp.
In a medium bowl, whisk together tahini, Dijon mustard, lemon juice, maple syrup, apple cider vinegar, and water. Add water gradually to reach the desired pourable consistency. Season with salt and pepper to taste.
Once everything is roasted, divide the vegetables and chickpeas among serving bowls. Drizzle generously with tahini dressing. You can serve it warm or at room temperature.