Heat a dry pan over low heat, add the Sichuan peppercorns, and toast them for 1-2 minutes until fragrant. Be careful not to burn them. Remove from the pan and let them cool, then coarsely grind them using a mortar and pestle or a spice grinder.

In the same pan, add the dried red chili peppers and toast them for 1-2 minutes until they turn slightly dark and fragrant. Remove from the pan and let them cool, then cut them into small pieces and remove the seeds if you prefer less heat.

In a small saucepan, heat the vegetable oil over low heat. Add the minced garlic and ginger, and sauté for 1-2 minutes until fragrant.

Add the ground Sichuan peppercorns, toasted dried red chili peppers, soy sauce, dark soy sauce (if using), black vinegar, sugar, and salt to the saucepan. Stir well to combine.

Simmer the sauce over low heat for 5-7 minutes, stirring occasionally, until the flavors meld together and the sauce thickens slightly.

Taste and adjust the seasoning with more salt or sugar if needed. Remove from heat and let the mala sauce cool to room temperature.

Once cooled, transfer the mala sauce to a jar or airtight container and store in the refrigerator for up to two weeks.