Remove the outer leaves from two freshly cut lemon grass stalks. Rinse under running water to remove any dirt or debris. Chop the two stalks into pieces about 3 inches long. Throw away any brown or dried pieces of stalk.
Place the cut lemon grass sections in a large saucepan. Add 4 cups of water to the pan. Put the saucepan on the stove and turn on the heat to high. When the water boils, turn the heat off. Leave the pan on the burner of the stove.
Wait 15 to 20 minutes while the lemon grass sections steep in the hot water. You will be able to smell the aroma of lemon grass tea throughout the house.
Hold a strainer over a teacup and pour the hot lemon grass tea through the strainer into the cup. Sweeten the tea by stirring in a little agave syrup if you like.