Heat oil over medium low. Add sweet potato, scallions and ginger and saute until softened, about 4 minutes.
Stir in the edamame, rice, coconut milk, lime juice, salt and water.
Bring to a boil, cover, reduce heat to simmer, and cook until rice is tender and liquid has been absorbed, about 15 minutes.
Use fork to fluff the rice, then stir in the lime zest. If desired, serve topped with peanuts.