Bring 2 cups water to boil with the 4 sticks of lemon grass in it. Simmer for 10 minutes. Add remaining 2 c. broth and the rice and continue to boil for an additional 10 minutes. Then remove the lemon grass. Continue to simmer until the rice is cooked, yet firm, about 10 minutes. Add the remaining ingredients. Cook an additional 5 minutes. Serve hot.