Press the tofu (just wrap the tofu in a clean towel and apply a steady weight to squeeze out moisture). This step is optional but highly recommended.
Cube the tofu and place the tofu cubes in a bowl or shallow dish.
Add the soy sauce, stir, and let it rest for at least 5 minutes.
In the meantime, add all the sauce ingredients to a bowl and mix until well combined. Set aside.
Whisk the slurry ingredients in a small bowl and pour them into the sauce bowl. Mix until well combined. Set aside.
Drain the tofu and transfer ⅓ of the tofu cubes into a freezer bag with 1 or 2 tablespoon of cornstarch and toss to coat. Repeat this step with the remaining tofu and cornstarch. Add more cornstarch if needed.
If you don’t want to use a freezer or plastic bag, just add the cornstarch to a shallow dish, then the tofu cubes, and toss to coat.
Once the tofu cubes are coated with the cornstarch, heat the oil in a skillet and add the tofu cubes.
Cook the tofu cubes over medium-high heat until all sides are golden brown. Then pour the sauce into the skillet and cook until it thickens.