Dashi is a clear Japanese stock that's often made with dried bonito (tuna) flakes and water. It is available in powdered form at Asian markets. In place of the dashi and water called for here, you can use 1 1/2 cups of low-sodium chicken broth mixed with 1 1/2 cups of water.
Sake: Soft, creamy Hoyo Genji Shining Prince Junmai. Pairing by Rick Smith and Hiroko Furukawa of New York City's East Village sake shop Sakaya (sakayanyc.com).