Preheat oven to 400˚. In a small roasting pan, combine diced rhubarb, maple syrup, and butter. Roast until rhubarb is tender, about 15 minutes. Remove from oven and let cool.
In a bowl, combine the yogurt with 1/2 cup cooked farro, and top with rhubarb mixture. If it's too tangy, add another small drizzle of maple syrup.