Wrap tofu block in a clean kitchen towel or paper towels. Place on a flat surface and set a heavy pan on top. Press for at least 15–30 minutes. Cut pressed tofu into 1-inch cubes.
Toss the tofu cubes with cornstarch, salt, and pepper until every surface is coated.
Heat oil in a large non-stick or cast iron skillet over medium-high heat until shimmering. Add tofu in a single layer — don't crowd. Cook undisturbed for 3–4 minutes until the bottom is deeply golden. Flip and cook 2–3 more minutes per side until all surfaces are golden and crispy.
While the tofu cooks, whisk together soy sauce, rice vinegar, honey, sesame oil, ginger, and garlic. In a small bowl, mix the cornstarch slurry.
Reduce heat to medium. Pour the sauce over the crispy tofu and toss to coat. Add the slurry and cook 1–2 minutes, stirring, until the sauce thickens and clings.
Serve over rice, topped with green onions and sesame seeds.