Preheat the oven to 425 F. Bring two cups of water to a boil in a small pot, then add the farro and return to a boil. Cover and reduce the heat to low. Cook for 25 minutes, until all the water is absorbed. (if using whole farro, bring 3 cups water to a boil and cook for 30-40 minutes, until tender, then drain.) Let sit, covered, while you prepare the asparagus.