Make the sauce: In a small bowl, whisk together the sugar, ketchup, apple cider vinegar, soy sauce, minced garlic and cornstarch. Set aside.
For the Tofu: Press the tofu: press tofu by wrapping in paper towel. Place a plate or pan on top of the wrapped tofu, place a couple of heavy book or a cast iron skillet on top of tofu. Or purchase a tofu press. It will make your life a little easier! Press tofu for 30 minutes to an hour. Cut the pressed tofu in 1 inch cubes and add to s large bowl. Drizzle soy sauce and stir gently with small spoon. Be careful not rip tofu. Now sprinkle on the cornstarch and gently stir to coat the tofu. Heat a large non-skillet or cast iron over medium- high heat. May need to more oil if using a cast iron skillet. Once skillet is hot, add tofu in a single layer. Let tofu brown on all sides, it should be a nice golden brown all over. Trans for to plate. Cook the vegetable Add another tablespoon of oil to the pan, if needed. Add pineapple, bell pepper and onions and cook for 2 minutes until crisp/tender.
Whisk sauce before adding to the pan, and cook for 1 minute, stirring constantly until the sauce thickens. Now add the fried tofu back to the panned stir, cooking for about 5 minutes until the sauce thickens. Serve immediately with cooked rice, green onions, pickled ginger and sesame seeds. Enjoy!