Heat the cooking oil in a deep cooking pot.
Deep fry the tofu. When the color turns light to medium brown, remove and set aside.
Meanwhile, heat a pan and then pour in a tablespoon of cooking oil (use remaining oil from fried tofu)
When the oil becomes hot, put-in the garlic and cook for 20 seconds.
Add the pineapple chunks, onion, green and red bell peppers. Stir and cook for 3 to 5 minutes.
Combine sugar, soy sauce, vinegar, water, and ketchup in a bowl. Mix well.
Pour-in mixture to the pan where the vegetables are cooking. Stir and let boil.
Pour-in the cornstarch diluted in water. Stir until the sauce thickens.
Add the deep fried tofu. Stir.
Transfer to a serving plate.
Share and enjoy!