Press the tofu for at least 15 minutes to remove excess moisture, then cut into even 1-inch cubes.
Mix the cornstarch with a pinch of salt and pepper on a plate. If desired, add a pinch of garlic powder or chili flakes for extra flavor.
Heat about 1 inch of oil in a deep skillet or wok over medium-high heat. Use a thermometer to ensure the oil reaches 180°C (350°F), or test with a small piece of bread—it should sizzle and turn golden in about 30 seconds.
Toss each tofu cube gently in the cornstarch mixture, ensuring an even, delicate coating. Shake off any excess before frying.
Carefully add the coated tofu in small batches to the hot oil, avoiding overcrowding. Fry for 3-4 minutes, turning occasionally, until the exterior is golden brown and crisp, and the surface crackles with a satisfying sound.
Use a slotted spoon to remove the crispy tofu from the oil, then transfer to a plate lined with paper towels to drain excess oil and maintain crispness.
Repeat frying with remaining tofu until all pieces are golden and crispy.
Once all tofu is fried, squeeze fresh lemon juice over the hot bites and sprinkle with toasted sesame seeds if desired for added aroma and flavor.
Give everything a gentle toss to coat evenly, then serve immediately while still crispy and hot for the best texture and flavor.
