In a large bowl, soak dried wood ear mushrooms in cold water for 2 hours until they’re fully rehydrated (see note for alternative methods).
Under tap water, wash one by one to remove dirt hidden in the folds. Snip off tough stems if any. Tear large ones into bite-sized pieces.
Bring a pot of water to a full boil. Blanch the mushrooms for 5 mins (You may need to reduce the time a little if your mushrooms appear extra thin).
Rinse under running water to cool then drain well.
Make the sauce
Put minced garlic, chili flakes/powder and ground Sichuan pepper in a heat-proof bowl. Heat oil until it smokes then pour over the garlic and spices.
Add light soy sauce, black rice vinegar and sugar. Mix well.
Combine the dish
In a large bowl, mix the mushroom, chili pepper, onion, coriander (if using) and the sauce until well combined.
Transfer to a serving plate/bowl. You may enjoy it immediately or refrigerate for a while for an even better taste.
It’s fine to soak the mushrooms overnight (in the fridge if your kitchen is quite warm). You may also use hot water to reduce the process to 20 mins (but the cold water method produces the best result in terms of texture).