Vegan Sweet and Sour 'Pork'

1. Remove firm tofu from its package, then drain and pat dry with a paper towel. Cut into 4 slabs (optional step) and freeze until hardened. If you freeze the tofu in a large block, it'll require more time for it to thaw to room temperature. 2. When ready to use, thaw tofu to room temperature, and squeeze out excess water. Be gentle with this step as the tofu 'sponge' can be quite delicate. 3. Break the tofu into pieces, then season with salt, pepper and rub them with a tablespoon of cornstarch. 4. Heat 1 cup of oil in a small tall pot to about 375°F (190°C) or use the chopstick method to test the oil temperature. 5. Coat tofu with another layer of cornstarch and slowly place in the hot oil and fry until golden brown on all sides. 6. Remove and set them on paper towels to absorb excess oil. 7. In a heated non-stick pan, add 2 teaspoons of oil and sauté the onion and bell pepper for about a minute. Dish out and set aside. 8. Using the same pan, add in the water with cornstarch, ketchup, rice vinegar, sugar, lemon juice, and salt. 9. Bring the mixture to a rolling boil while stirring continuously. Then, lower to simmer and cook until the sauce is slightly thickened. 10. Add the pineapple and sautéed veggies,stir to combine, then cook for about 30 seconds. 11. Finally, place in the cooked tofu and toss everything together until well combined and season with salt. 12. Transfer to a serving bowl and serve warm.