Teriyaki Sauce

1 cup soy sauce
5 Tablespoons ketchup
1 cup sugar
1/3 cup cornstarch dissolved in 1/3 cup water
1 cup sake or dry sherry
3 Tablespoons apple juice
one pinch black pepper

Combine all ingredients in a saucepan, except cornstarch mixture.
Cook for 10 minutes over medium heat.
Gradually stir in dissolved cornstarch solution until mixed well.
Continue cooking until thickened.
Stir well before serving.