Shell 1/2 lb shrimp. rinse shrimp and shells. put 4 cups water in pot with shells and bring to boil. Strain out shells. you now have shrimp stock.
Add Shrimp. 1/2 lb ish
Add Mushrooms 1/2 cup sliced or so
Bring Shrimp and Mushrooms to boil.
Reduce heat to medium.
Add 1 stalk lemon grass. bottom 1/3 only cut into 1 inch pieces.