To get a head start: Make the farro, as in step 1, ahead. The stew, as in step 3, can be prepared up to 3 days ahead. Reheat before adding the mussels and farro, as in step 4. The mussels should be bought the day they are cooked. For a speedy, light dish, omit the farro altogether, and do not add the water to the stew.
To vary it: Easily available and affordable pearl barley plumps up nicely to compete with farro in this dish, or simply use leftover brown rice. You will need about 2 cups cooked grain.
Reprinted with permission from Ancient Grains for Modern Meals by Maria Speck, copyright © 2011. Published by Ten Speed Press, a division of Random House, Inc. Photo credit: Sara Remington © 2011