Wash and peel the shrimp, then clean them thoroughly. Pound the chilies and prepare the vegetables.

Bring a moderate amount of water to a boil and add the salt. Once boiling, briefly blanch the shrimp heads and shells to make a broth, then remove and set aside.

Add all the Tom Yum herbs (galangal, lemongrass, kaffir lime leaves), chilies, and shallots to the pot.

When the herbs are fragrant and boiling, add the mushrooms. Season with fish sauce and lime juice, then add the cleaned shrimp.