In a bowl combine sauce ingredients.
Dice your tofu into 1 inch by 0.5-inch cubes.
Place cornstarch on a plate and generously coat your tofu in the starch with gentle hands. Do this in a few batches. Once tofu is coated, set aside. Warning: Do not place tofu in a bowl and dump starch on top. This will make it difficult to coat tofu without breaking apart the tofu, even with your hands.
In a hot non-stick pan set over medium heat, add oil followed by tofu. Allow the tofu to fry on top and bottom until golden and crispy (7-10 minutes per top and bottom, 14-20 mins in total). Note: 7 minutes for crispy or 10 minutes for extra crispy. Remove crispy tofu from pan and set aside.
Into the hot pan, pour in sauce and let this bubble to thicken and reduce. Once thickened, mix in tofu until coated. Optional: garnish with green onions and sesame seeds. Enjoy!