This was one of my favorite things to eat when I lived in China. This recipe is super loosely based on Francis Lam's recipe.
Process:
Heat neutral oil in a frying pan. Beat eggs with MSG and a dash of sesame oil. Once the oil is hot, add the eggs. Scramble the eggs; remove from the pan when they are just set. Add more oil to the pan and add some scallions. Once hot, add tomato (cut into wedges) and season with salt and MSG. Add a dash of shaoxing rice wine, dry sherry, or mirin. Sauté until the tomatoes start to release moisture. Once they are pretty soft, add a corn starch slurry (approx. 1 tsp corn starch dissolved in a few tablespoons water). Bring the mixture to a boil and lower the heat once the liquid thickens. Return the eggs to the pan and toss so they are coated in the sauce. Garnish with scallions.
TIP:
Make sure the corn starch is fully dissolved in the water. If it isn't, you run the risk of a grainy texture.