Combine broth and water in a small pot and bring to a boil over high heat. When it boils, add orzo. Bring back to a boil, then cover and simmer for 5 to 6 minutes, until most of the liquid has cooked off.
Remove from heat and stir in oil, zest, and salt. Taste, adjust seasoning as desired, and serve immediately.
Recipe courtesy Aida Mollenkamp