Sauce:
Toss the shrimp in a bowl with the salt.
Dust the shrimp with the cornstarch, and coat in the egg white.
Drop enough batter onto a greased griddle to make a pancake of approximately 3" diameter.
Make sure some slices of apple get into every one.
In a second pan (or the first, if you remove the shrimp ), over high heat, stir-fry the garlic in a little more oil, with half the scallions, and the tomatoes, for half a minute.
Add the tomato sauce, salt sugar, and stock.
Continue to cook for about a minute.
Stir in the blended cornstarch and thicken the sauce.
Add the sesame seed oil and the remaining scallions.
Add the shrimp again, blend all well, and serve with rice.