Cut the pork into small cubes and place them in a large bowl. Add salt, ginger and light soy sauce. Set aside for 15 minutes. Crack the egg in and then mix in around 1/4 cup of cornstarch.
Add 1/2 cup of cornstarch in a plate and coat the pork cubes with starch. Make sure each piece is dry and isolated.
Prepare other side ingredients. And prepare the sweet and sour sauce in advance. Heat up vegetable oil in pan or wok; add garlic, green onions and ginger to stir-fry over small fire. until aroma with low fire. Then fry the ketchup for a while and then add water, light soy sauce, rice vinegar, sugar and water starch. Simmer for around 1 minute until the sauce is well thickened.
Add a very little amount of oil in wok and fry pineapple cubes and bell peppers until soft.
Add well made sweet and sour sauce in. Around 4 tablespoons.
Return fried pork cubes and toss the wok quickly to make each pieces of the pork coated with sweet and sour sauce. Serve hot.