Add the water and farro to a small saucepan, and let it sit while you cut the onions, garlic and tomatoes.
Add the sliced onion, sliced garlic and halved tomatoes to the saucepan, along with the salt and olive oil.
Bring to a boil, then reduce to a simmer, stirring occasionally for around 15-20 minutes.
The farro is cooked when the liquid is almost all absorbed, and the farro is tender (will have a chewy bite to it but will not be hard)
Transfer to a serving dish,
Garnish with with the basil and parmesan.