In a bowl, mix together garlic, chili peppers (if using), soy sauce, dark soy sauce, oyster sauce, salt, sugar, corn starch, and water.

Drain the tofu and pat it dry with a towel. Cut tofu lengthwise in half, then crosswise into 1/2-inch thick pieces.

Place 1 cup of corn starch in a shallow bowl and the beaten egg in another bowl.

Heat a generous amount of oil (enough to cover the base) in a large non-stick skillet over low-medium heat.

Dip each tofu piece in the prepared corn starch first. Ensuring all sides are coated, and shake off any excess corn starch, then dip the tofu piece in the beaten egg. Immediately transfer the tofu piece into the skillet.

Repeat the above step with the rest of the tofu pieces.

Arrange the tofu pieces in the skillet in a single layer.

Turn the heat up to medium and cook each side for about 2-3 minutes until golden brown and crispy. Use paper towels to blot out some of the excess oil if necessary.

Mix the prepared sauce again until the corn starch is dissolved.

Turn the heat down to low-medium, then pour the prepared sauce over the pan-fried tofu pieces. Carefully toss or flip the tofu pieces a few times with a spatula, ensuring they are evenly coated with the sauce.

Turn off the heat once the sauce starts to thicken.

Transfer everything to a plate and garnish with some sesame seeds on top if desired.

Serve hot with some white rice and enjoy!