Make stir-fry sauce by adding soy sauce, cider vinegar, garlic and ground ginger to broth and water. Mix in brown sugar, and add cornstarch as a thickening agent. The sauce can be refrigerated for up to two weeks.
Pour 1 1/2 cups of vegetable, chicken or beef broth and 1/2 cup of water into a jar. Add 1/4 cup of cider vinegar and 1/2 cup of soy sauce. Season with 1/4 cup of brown sugar, 1/4 teaspoon of ground ginger and 2 minced garlic cloves. Mix in 2 to 3 tablespoons of cornstarch, and screw on the jar's lid. Shake the mixture well before using or storing. When cooking with the sauce, bring it to a boil until the sauce starts to thicken.
Another good stir-fry sauce calls for light soy sauce, dark soy sauce, oyster sauce and Chinese wine. In a jar, pour 1/4 cup of light soy sauce, 1/4 cup of dark or normal soy sauce, 1/4 cup of Chinese wine or sherry and 1/4 cup of cornstarch. Add 1/2 cup of oyster or hoisin sauce, 2 tablespoons of sesame oil, 1 tablespoon of sugar and 1 tablespoon of white pepper. Add the sauce to the stir-fry at the end of the cooking time, and cook only until it thickens.