Kung Pao sauce is such a popular and classic sauce that every chef has their own interpretation. It can be extra spicy, more savory, or syrupy. The version I like the most is the type that balances savory, sweet and spicy with a gentle numbing sensation and a little extra sour kick.
Combine Chinkiang vinegar, light soy sauce, Shaoxing wine, sugar, cornstarch, and salt in a small bowl. Set aside.
Add peanut oil, chili pepper flakes, and sesame seeds in a sauce pan. Cook over medium low heat until it reaches a gentle sizzle. Turn to medium low heat. Cook and stir until the chili powder turns dark brown (without turning black). If the oil start to bubble fiercely, remove the pan from the heat.
Add ground Sichuan peppercorns, garlic and ginger. Cook and stir for another 30 seconds to release fragrance.
Stir the vinegar-based sauce with a spoon to dissolve cornstarch completely. Carefully add to the saucepan. Cook and stir until the sauce thickens just enough to coat a spoon (the sauce will thicken once cooled down). Transfer to a bowl immediately.
Once the sauce is cooled down completely, transfer to an airtight jar. Store in the fridge for 1 to 2 weeks. Store the sauce in the freezer for longer period of time.
Korean chili flakes are quite mild and are suitable for using in this sauce. If you’re not sure about the heat level of your chili flakes, start with 1 teaspoon chili flakes so your sauce won’t turn out too spicy. Alternatively you can use 1 teaspoon cayenne powder.