Blend the shrimp with a pinch of the salt, the egg white, and about half the cornstarch paste.
Heat some peanut oil in a preheated wok or pan. Stir-fry the shrimp for about 1-1/2 minutes, remove with a strainer and drain.
Pour off the excess oil, leaving about 1 tablespoon in the wok or pan. Stir-fry the garlic, the tomatoes and white parts of the scallions for about 30 seconds, then add the remaining salt together with the tomato paste, sugar, soy sauce, rice wine and stock. Blend well and bring to the boil.
Add the shrimp with the green parts of the scallions. Blend well and thicken the sauce with the remaining cornstarch paste. Sprinkle the sesame oil and serve hot, garnished with cilantro leaves.