Lightly toast the whole Red Sichuan Peppercorns in a dry skillet over medium heat, shaking the pan, until fragrant and slightly darker—about 1–2 minutes. Remove from heat and let cool briefly.
Crush or bruise the toasted peppercorns coarsely using a mortar and pestle or the flat side of a knife; you want broken pods, not a fine powder.
Place the crushed peppercorns into a heatproof, oven-safe bowl or jar. Measure out the Neutral Oil and have it ready nearby.
Heat the oil in a small saucepan over medium heat until it is hot and shimmering but not smoking (you should see faint wisps and a few gentle ripples). Remove from heat.
Carefully and slowly pour the hot oil over the crushed peppercorns—the oil will sizzle and bloom the aromatics. Stir gently to combine and release the flavors.
Allow the mixture to cool to room temperature, then transfer to a clean jar. For a clearer oil, strain through a fine-mesh sieve or cheesecloth; for stronger flavor, leave the solids in.
Store the oil in an airtight container in the refrigerator for up to 2–4 weeks. Use as a finishing oil for dumplings, noodles, salads, stir-fries, or to add a fragrant, numbing kick to sauces and marinades.
