3 Eggs, slightly beaten
6 pieces Prawn, peeled, left tail only, butterfly
3 pieces Straw mushroom, divided
6 stems Lemongrass, sliced
50 g Galangal, sliced
5 Red chili, sliced
3 Kaffir lime leaf
3 tablespoons Fish sauce
Drain coconut juice and keep the shells.
Bring 550 ml of coconut juice to boil.
Pound sliced lemongrass and galangal, whole chilies and kaffir lime leaves.
Add to the boiling coconut juice and season with fish sauce.
Let it boil for 5 minutes.
Beat eggs in a bowl and set aside.
Strain tom yum broth.
Measure 350ml of strained broth, add into the egg mixture little by little, stir well and pour into the coconut shells.
Put the coconut shells into the steamer, steam at high heat for 3 minutes, then reduce the heat and steam for another 25 minutes.
Bring the leftover broth to boil.
Add sliced mushrooms and prawns.
Mix cornstarch with a tablespoon of water, pour into the broth.
Bring to boil again.
Turn off the heat and set aside.
Prepare slice chilies for garnish.
When the steam eggs are cooked, take them out from the steamer and garnish with cooked prawns, a piece of coconut flesh, mushrooms, chilies and kaffir lime leaves.
Pour the thick sauce and serve.