Press the firm tofu for 15 minutes to remove excess moisture then cut into 1-inch cubes.
Cut the chicken breast into bite-sized pieces and toss both the chicken and tofu in a bowl with cornstarch, sea salt, and black pepper until lightly coated.
Heat the sesame oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken and tofu to the pan and sear until golden brown and crispy on all sides, which should take about 6 to 8 minutes.
Add the broccoli florets and sliced red bell pepper to the skillet and stir-fry for 3 to 4 minutes until the vegetables are crisp-tender.
In a small bowl, whisk together the tamari, honey, grated fresh ginger, and minced garlic to create the glaze.
Pour the sauce over the chicken and vegetable mixture and toss for 1 minute until the glaze thickens and coats every piece beautifully.
Garnish the stir-fry with sesame seeds and serve immediately while hot.