Crack eggs into a small bowl. Add water. Season with salt. Whisk until the mixture has just one consistency.
Meanwhile heat 1/2 tablespoon oil in a large skillet or frying pan. Add egg mixture. Let it sit, without stirring, for about 20 seconds. Gently stir with a wooden spoon, lifting and folding it over from the bottom of the pan.
Repeat this process until the eggs are softly set and slightly runny in places. Remove from pan. Set aside.
To the same pan, add the remaining 1/2 tablespoon oil. When hot, add garlic and spring onion (scallion) whites. Sauté, stirring, for a minute.
Add tomatoes. Sauté, stirring occasionally, for about 2 minutes or until the tomatoes are cooked.
Add oyster sauce, sesame oil, sugar and ground white pepper. Season with salt. Stir to combine. Sauté for 1 minute.
Add scrambled eggs. Stir gently to combine.
Garnish with chopped spring onions. Serve with steamed rice.