In a bowl, combine soy sauce, broth, rice wine, sugar, sesame oil and white pepper. (See note in intro about the soy sauce). Dissolve the cornstarch in 1/4 cup water. Heat a pan over high heat; add the cooking oil, swirling to coat; add the garlic and ginger; cook, stirring, until fragrant, about 15 seconds. Add the soy sauce mixture; bring to a boil. Reduce heat to medium and cook for 1 minute. Add the cornstarch solution and cook, stirring, until the sauce boils and thickens.