Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Press the firm tofu for at least 15 minutes using a tofu press or heavy skillet to remove excess water, then slice into 1-inch cubes.
In a large mixing bowl, whisk together the tamari, garlic powder, and onion powder, then toss the tofu cubes until well coated.
Sprinkle the nutritional yeast over the tofu and toss again until each cube has a thick, even coating for maximum crunch.
Cut the broccoli into small florets and thinly slice the red bell pepper into bite-sized strips.
Spread the tofu and vegetables onto the prepared baking sheet in a single layer, drizzle with olive oil, and season with sea salt and black pepper.
Bake for 25 to 30 minutes, flipping the tofu halfway through, until the edges are golden brown and the vegetables are tender-crisp.
Stir in the shelled edamame during the final 5 minutes of roasting, then finish with a bright squeeze of fresh lemon juice before serving.