Avgolemono (Egg Lemon Soup)

Make chicken broth and heat to boiling; add rice. Simmer covered about 20 minutes. Remove from heat and set aside. In a bowl, beat egg whites until stiff; add yolks and beat well. Beat continuously adding lemon juice a little at a time. Then add about 1/5 of the broth, beating continuously. Pour this mixture back into the pot of broth and rice. Mix well over heat but, to avoid curdling, do not allow soup to come to a boil. Serve immediately.