1-Spread the cubed tofu on a paper: Spread the cubed tofu on a paper towel or clean, lint-free kitchen towel. Top with another layer of paper towels or a second clean kitchen towel. Top with something flat and heavy and let the tofu sit like that for at least 15 minutes or up to an hour.
2-In a shallow bowl, combine cornstarch, salt: In a shallow bowl, combine cornstarch, salt and pepper. Toss tofu in it to coat each side.
3-Heat a non-stick skillet with one tablespoon: Heat a non-stick skillet with one tablespoon of oil and fry tofu on each side until golden brown. Remove and place on a plate with kitchen paper to absorb the excess of oil. Set aside.
4-Add the remaining one tablespoon of oil: Add the remaining one tablespoon of oil to the skillet and sauté the garlic, onion, bell pepper, and cashew nuts until fragrant. It will take about 3 minutes. Bring back the tofu.
5-Meanwhile, stir sauce ingredients in a bowl: Meanwhile, stir sauce ingredients in a bowl. Pour in the skillet. Stir all together and bring to a simmer for one minute. It will thicken a little bit. Simmer longer if you want a thicker sauce.
6-Remove and garnish with green onions: Remove and garnish with green onions.