Boil water in a 2 quart pot. Peel and de-vein the shrimp and set them aside. Cut lemon grass into pieces, 5-6 inches long. Use the back of your knife to pound the lemon grass, just to bruise it to release the flavor. Tie the lemon grass into a knot to make it easier to manage. Drop the lemon grass in water and let boil for 5 minutes.