For a vegetarian option, substitute the ground pork with crumbled tofu or finely chopped mushrooms. Adjust the amount of Sichuan peppercorn powder to your preference. For a milder flavor, use less; for a more intense experience, use more. If you don't have Sichuan peppercorn powder, you can lightly toast Sichuan peppercorns in a dry pan and then grind them using a spice grinder or mortar and pestle. Make sure the vermicelli doesn't overcook and become mushy. It should be tender but still have a slight bite.