Heat a wok or large skillet over medium high heat until hot. Add oil and peppercorns. Stir until the peppercorns become fragrant and turn dark brown. Turn the heat right down and scoop the peppercorns out with a spatula and put aside for later. (*footnote 1).
Turn the heat back to medium high and add the chili peppers and cabbage. Immediately stir with spatula for 30 seconds. You should hear a vibrant sizzle. Add the salt. Keep stirring until the the edges are lightly charred and the leaves turn soft, 2 to 3 minutes.
Turn to medium low heat, drizzle soy sauce over the cabbage and stir a few times to mix everything well.
When the Sichuan peppercorns cool down, grind them in a coffee grinder and store in an airtight container in the fridge. The peppercorn powder is very fragrant and can be used in making marinade or sauce, such as sesame noodles.