Marinate meat in a mixture of 1/4 cup soy sauce and sugar for 1/2 hour.
Meanwhile, cook garlic and ginger in oil for a few minutes.
Add green peppers.
Saute, stirring constantly, for a few minutes.
Add beef and liquid.
Cook another few minutes.
Simmer a few minutes until tomatoes are hot.
Blend cornstarch with 3 tablespoons soy sauce.
Stir into mixture.
Cook 1 minute more until thickened.