Preheat oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Press the tofu with a clean towel to remove excess moisture, then cut into half-inch cubes.
Rinse and drain the chickpeas, patting them completely dry with a paper towel to ensure they get crispy.
Place the tofu, chickpeas, broccoli, and cauliflower on the prepared baking sheet.
Sprinkle with garlic powder, onion powder, sea salt, and black pepper, tossing well to coat evenly without oil.
Roast for 25 to 30 minutes, tossing halfway through, until the vegetables are tender and the tofu is golden.
In a small bowl, whisk together the lemon juice and nutritional yeast to create a thick dressing.
Transfer the roasted mixture to a bowl, drizzle with the lemon-yeast mixture, and top with hemp hearts.