Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Press the extra firm tofu for at least 15 minutes to remove excess moisture, then cut it into 1-inch uniform cubes.
Peel the sweet potato and dice it into small 1/2-inch cubes to ensure they roast at the same rate as the tofu.
In a large mixing bowl, toss the tofu cubes and sweet potato with the olive oil, garlic powder, sea salt, and black pepper until well coated.
Spread the mixture in a single layer on the prepared baking sheet and roast for 15 minutes.
Remove the tray from the oven and add the broccoli florets and trimmed green beans, tossing them gently with the roasted items.
Return the tray to the oven and bake for another 15 to 20 minutes until the tofu is golden and the vegetables are tender.
While roasting, whisk the tamari and nutritional yeast together in a small bowl to create a savory, protein-rich seasoning paste.
Transfer the roasted ingredients to a serving bowl, add the rinsed black beans, and toss everything with the tamari-yeast mixture before serving warm.