Drain the water in the package from the block of tofu, then use your hands to tear the tofu into medium bite-sized pieces (see Tip). 

In a large bowl, combine the tofu pieces, cornstarch, white pepper and salt. Toss the tofu around in the bowl until all the pieces are coated.

Fill a deep pot with enough oil to deep-fry the tofu and bring the oil to 3750º (191ºC). Deep-fry the tofu pieces for 5 to 7 minutes or until the exterior becomes crispy with a light brown color. Remove the tofu pieces from the oil with a slotted spoon, and place them on paper towels or a rack to drain.

In a large nonstick pan over medium-high heat, heat 1 teaspoon of the same oil that you used to deep fry. Add the ginger, red pepper chili flakes and garlic, and cook for about 30 seconds until the garlic turns slightly brown. Add the sugar, orange juice, vinegar and tamari, then stir until the sauce has reduced, about 5 minutes.

Add the tofu to the pan and gently stir until all the pieces are coated with the sauce. Mix in the orange zest and turn off the heat. Once the heat is off, mix in the sesame oil and serve hot with steamed jasmine rice and green onions.