Step 1

Before starting the sauce prepare the Szechuan peppercorns by toasting around 2 tablespoons in a sauté pan over medium heat for 5 minutes or until fragrant and slightly darkened. Grind the toasted peppercorns in a spice grinder, coffee grinder, or mortar and pestle until fine, and then sift it through a wire mesh strainer to remove the big pieces.

Step 2

Make the sauce by combining 1 cup of water with soy sauce, sesame oil, ginger, garlic and salt in a small saucepan over medium heat. When the mixture begins to bubble reduce the heat and simmer for 12 minutes. Cover the pan and let the mixture steep for 12 minutes, then pour the sauce through a wire mesh strainer. Add the strained sauce back into the saucepan.

Step 3

Mix 2 tablespoons of cornstarch into the remaining 1/2 cup of water until dissolved. Pour this slurry into the saucepan along with the sugar, ground Szechuan peppercorns, black pepper, and coriander. Heat over medium until bubbling, then reduce the heat and simmer for 3 minutes. It should be much thicker. Remove the sauce from the heat and let it cool for 3 minutes, uncovered.

Step 4

Add the vinegars and lime juice, and let it cool down before using. Store the sauce covered in your refrigerator and it will last for several weeks. Stir well before using.