Natchio's Restaurant Avgalemeno sauce

This is the sauce that is added to Natchio's Restaurant delicious lemon chicken soup. Use also with chicken or fish.

3 eggs, separated
4 tablespoons lemon juice, or juice of 1 large lemon
2 cups chicken broth

Beat the egg whites and yolks separately, then together until they are blended. Gradually beat in the lemon juice and 2 cups of boiling chicken broth. Don't let it curdle. If you use this sauce in soup, heat the soup and add the sauce, stirring constantly.