Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Press the extra firm tofu with a heavy object for 10 minutes to remove excess moisture, then cut into 1-inch cubes.
In a large bowl, toss the tofu cubes, sweet potato, broccoli, and chickpeas with the olive oil, sea salt, black pepper, and garlic powder.
Spread the vegetable and tofu mixture in a single layer on the prepared baking sheet.
Roast for 25-30 minutes, tossing halfway through, until the sweet potatoes are tender and the tofu is lightly golden.
While the vegetables roast, whisk together the tahini, lemon juice, maple syrup, and nutritional yeast in a small bowl, adding 1-2 tablespoons of warm water to achieve a smooth, pourable consistency.
Place the cooked quinoa in the bottom of a serving bowl and top with the roasted tofu and vegetable mixture.
Drizzle the zesty tahini sauce over the bowl and garnish with hemp seeds before serving.