Bring broth to a boil in a 3 quart saucepan over medium heat. In a medium bowl, whisk eggs, lemon juice and lemon pepper until well blended, then slowly whisk in 1 cup of the hot broth. Lower heat; add egg mixture, stirring constantly. Cook over low heat, stirring until heated through. (Don't boil! Eggs will curdle.)
Remove from heat and stir in lemon zest. Ladle into serving bowls and sprinkle each serving with a little Parmesan.