Heat oil in a large sauté pan, and sauté onions for about 5 minutes on medium-high heat until golden.
Add sundered tomatoes and garlic and saute for another minute. Add the farro and sauté for about 30 seconds to toast farro.
Add the wine if using, and stir until the liquid is absorbed.
Add about 2 ¼ cups of the chicken stock to the pan. Stir to combine and bring the mixture to a boil.
Reduce heat to low, cover, and let the farrotto simmer for 30 minutes or until Farro is tender.
For a creamy farrotto, add extra liquid as needed, about ¼ cup at a time until the grains are cooked to the desired consistency. This should take about 10 more minutes.
Stir in arugula or other greens and let them wilt.
Add the fresh basil and stir to combine. Taste and season with salt.
Add cheese if desired.
Serve with additional grated cheese if desired.