Place the tofu on a cutting board, covered with a clean kitchen towel or paper towels. Place some books or a heavy object on it for about an hour, to allow the excess moisture to drain out.
Chop the tofu into cubes, then place them in the large bowl.
Toss the tofu with the cornstarch until fully coated and set aside.
In a small bowl, mix together all the ingredients for the sauce and set aside.
Add 2 tbsp of the oil to a large pan or skillet over medium-high heat. When hot, add in the garlic, onion, pepper and tomatoes.
Cook for about 7 minutes, stirring until the vegetables have softened.
Remove the vegetables from the skillet and add in the other 3 tbsp of oil, making sure it coats the skillet.
Shake the extra cornstarch off and add the tofu cubes into the skillet. Allow them to cook about 2 minutes per side, until golden brown. Stir the tofu around on the same side to ensure it doesn't stick to the pan.
Pour the sauce mixture over top of the crispy tofu pieces, stirring for about 5 minutes or until thickened.
Add the pepper mix in with the tofu, stirring everything together to fully coat with the sauce.
After another minute, turn off the heat and serve with white rice or a grain of choice. Enjoy!