At least 1 hour in advance, completely submerge the tofu skin in a bowl of cool water until it becomes pliable. Once soft, slice tofu skin into 2cm segments.
Trim the leaves off the celtuce and reserve for another use. Peel the lighter, fibrous outer layer then slice diagonally into 2mm ovals. Wash the wood ear mushrooms and tear larger ears into bite size pieces. Bring a pot of water with 1 Tbsp salt to a boil. In a large bowl, make an ice bath with equal parts ice and water.
Add tofu skin, celtuce, and wood ear mushroom to the pot. Blanch for 2 minutes then remove with a slotted spoon into the ice bath to halt cooking.
Drain and squeeze ice water from the ingredients and transfer to a large mixing bowl. Season with 1 tsp kosher salt, 1 tsp sugar, 2 tsp black or rice vinegar, 1 tsp Sichuan peppercorn oil, and a pinch of MSG. Mix well and taste, adjusting seasoning to your preference.
Serve immediately for best texture.
