1. In a bowl, add salt, garlic powder and white pepper to flour. Pour in water and mix in beaten egg until batter is slightly lumpy.
2. Batter shrimp (or pork) and fry until lightly golden brown. Set aside for the sweet and sour.
3. Heat oil in a wok and fry the garlic until golen color. Add cucumber, onion and stir until nearly cooked, then add tomatoes. Stir until all cooked.
4. Add the shrimp (or pork), white vinegar, fish sauce and sugar (add more vinegar, sugar and fish sauce according to your desired taste - the original taste should be a nice balance between sour, salty and sweet taste.)
5. When it starts to boil, thicken with the diluted corn starch. Served with steamed rice.