Drain the tofu and pat it dry with paper towels. Dice the tofu into small cubes.

Heat the cooking oil in a pan over medium heat. Fry the tofu cubes until golden brown and crispy. Set aside on a plate lined with paper towels to drain excess oil.

In a pan, heat 2 tablespoons of cooking oil. Sauté the garlic until fragrant and the onion becomes translucent.

Add the red and green bell peppers, and cook for about 2-3 minutes until they are slightly tender.

Add the fried tofu back into the pan. Pour in the soy sauce, oyster sauce, and calamansi or lemon juice. Season with ground black pepper and salt to taste. Stir well to coat the tofu and vegetables evenly with the sauce.

Add the mayonnaise and sugar. Stir well to coat the tofu and vegetables evenly with the mayonnaise.

If you prefer a spicy kick, add the chopped red chili at this stage. Mix everything thoroughly and cook for another 2-3 minutes.