1. In a medium saucepan, bring broth and water to a boil over high heat. Cover and remove from heat.
2. In a medium pot, heat oil over medium heat. Add onion and pepper and cook, stirring occasionally, until softened, 6 to 8 minutes. Stir in farro, salt and pepper and cook 1 minute. Add wine and continue cooking, stirring constantly, until liquid is absorbed, about 3 minutes.
3. Add two ladlefuls broth mixture to pot and cook, stirring constantly, until liquid is absorbed. Continue process with remaining broth mixture until grains are tender, about 20 minutes. Stir in asparagus and continue cooking until asparagus is crisp-tender and mixture is creamy, about 5 minutes. Remove from heat and stir in peas, Parmesan, parsley and lemon zest.