Press tofu with a heavy object for 15 to 20 minutes, then cut into cubes. Toss tofu cubes with 1.5 tablespoons cornstarch, 1/4 teaspoon each of white pepper powder and salt. Set aside.
Heat 1 tablespoon of oil on medium heat in a skillet. Once the oil is hot, add the cornstarch tossed tofu cubes to the skillet in single layer.Cook until each side is golden-brown, around 5 to 6 minutes each side. Remove tofu from the skillet into a plate.
Meanwhile, in a measuring jar or bowl, whisk together all the ingredients for the sauce- tamari, rice vinegar, brown sugar, toasted sesame oil, 2 teaspoons cornstarch and 2 tablespoons water. Set aside.
To the same skillet in which the tofu was pan-fried, now add the remaining 1/2 tablespoon of oil. Add in the chopped garlic and ginger and saute for 1 minute until the garlic and ginger start changing color.
Then add in the broccoli florets along with 4 tablespoons of water. Stir and cover the skillet with a lid. Cook/steam the broccoli for 2 minutes on medium heat.
Remove the lid and stir in the prepared sauce. It will start to thicken immediately.
Stir in the pan-fried tofu and turn off the heat. Mix until all the tofu and broccoli is well coated with the sauce. Add in the roasted cashews and green onion.
Garnish the tofu broccoli stir-fry with sesame seeds and serve warm with rice!
You may use soy sauce in place of tamari. This dish just don't be gluten-free then.
If you don't have cashews, you can even add peanuts here.