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 each piece is evenly coated.
Heat the toasted sesame oil in a large non-stick skillet over medium-high heat and sear the tofu until golden and crispy on all sides.
Add the broccoli florets to the skillet with a small splash of water, then cover with a lid for 2 minutes to steam-tenderize the vegetables.
Remove the lid and stir in the shelled edamame, minced garlic, and grated fresh ginger, sautéing for an additional 2 minutes.
In a small jar, whisk together the tamari, rice vinegar, and maple syrup, then pour the mixture over the tofu and vegetables.
Toss the stir-fry continuously for 1 minute until the sauce thickens and creates a glossy glaze over the ingredients.
Transfer the stir-fry to a plate and garnish with toasted sesame seeds before serving immediately.