Press the firm tofu for 15 minutes to remove excess moisture, then cut it into 1-inch cubes.
In a medium bowl, toss the tofu cubes with cornstarch, sea salt, and black pepper until they are evenly coated.
Heat the sesame oil in a large non-stick skillet over medium-high heat.
Add the tofu to the skillet and sear for 8-10 minutes, turning occasionally, until all sides are golden and crispy.
Add the broccoli florets, sliced red bell pepper, and shelled edamame to the pan and sauté for 5 minutes until tender-crisp.
Stir in the minced garlic and grated fresh ginger, cooking for 1 minute until the aromatics are fragrant.
Pour the tamari over the mixture and toss well to ensure the tofu and vegetables are thoroughly glazed.
Remove from heat, garnish with sesame seeds, and serve immediately.