Press the liquid out of the tofu either using a tofu press, or by placing a clean towel on top and gently pressing out as much moisture as you can.
Slice the tofu into small cubes, then add soy sauce, olive oil, salt and cornstarch to the bag and mix it until the tofu is coated.
Add the tofu in air fryer and cook it until it's nice and crispy on all sides, about 10 minutes.
While the tofu is cooking, make the sauce: whisk the butter, soy sauce, sriracha, lime juice, salt and cornstarch together in a small bowl.
Heat the skillet on a medium flame, then pour in the sauce and air-fried tofu, stirring until the tofu is coated. It will thicken very quickly, so this shouldn't take long.
Sprinkle with green onions and enjoy!