Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Press the extra firm tofu between paper towels to remove excess moisture, then cut into 1/2-inch cubes.
In a large mixing bowl, combine the tofu cubes, chickpeas, broccoli florets, and chopped red bell pepper.
Drizzle with olive oil and sprinkle with garlic powder, sea salt, and black pepper, tossing well to ensure everything is evenly coated.
Spread the mixture in a single layer on the prepared baking sheet and roast for 25 minutes, tossing halfway through, until the tofu is golden and vegetables are tender.
While the vegetables roast, whisk together the tahini and lemon juice in a small ramekin, adding a teaspoon of warm water at a time until it reaches a smooth, drizzling consistency.
Transfer the roasted tofu and vegetable mixture to a serving bowl.
Top with nutritional yeast and hemp hearts, then finish by drizzling the lemon-tahini dressing over the top.