remove the shrimp shell but leave the tails (for look).then cut open the back of each shrimp to remove the veins. clean the mushrooms with water
and dry them well before wedging each into quarters.Bring water to boil,then add lemon grass,lime leaves,and shrimps.when the shrimps turn pink ,add mushrooms and salts.remove the pot from heat after boil. add fish sauce,lime juice,and guinea-pepper