Prep the aromatics: Dice the scallions into small rounds and grate the peeled ginger. Place both into a medium heat-proof bowl, such as a ceramic or oven-safe bowl.
Add seasonings: Add the sesame oil, salt, white pepper, and Sichuan peppercorn powder (if using) to the bowl with the aromatics.
Heat the oil: In a small, heavy-bottomed saucepan, add the avocado oil. Heat it over medium-low heat, uncovered, for about 7–8 minutes, until the oil simmers. To check if the oil is ready, insert a dry chopstick into the oil—if small bubbles form around it, the oil is hot enough.
Activate the sauce: Slowly and carefully pour the hot oil over the scallions and ginger in the bowl. The mixture will sizzle immediately. Stir with a spoon to combine, and let the scallions soften for a few minutes.
Storage: Once the sauce has cooled to room temperature, transfer it to an airtight glass container. Store in the fridge for up to 1 month, but for the freshest flavor, use it within the first 2 weeks.
