How to Make It
Heat 1/4 cup of the olive oil in a large saucepan. Add the fennel, onion, garlic and a generous pinch of salt. Cook over moderate heat, stirring occasionally, until the fennel is softened, about 8 minutes. Add the stock and farro and bring to a boil over high heat. Reduce the heat to moderate and simmer, stirring occasionally, until the farro is tender and the stock is absorbed, 25 to 30 minutes.
Meanwhile, preheat the oven to 425°. On a large rimmed baking sheet, toss the sweet potato with the remaining 3 tablespoons of olive oil and season with salt and pepper. Drizzle with the sherry vinegar and roast for about 15 minutes, until just starting to soften. Add the apples and toss to coat. Roast for about 20 minutes longer, until the sweet potato and apples are tender but not falling apart. Let cool slightly.
In a large bowl, toss the farro mixture with the dried cherries, cashews, parsley and the roasted sweet potato and apples. Season with salt and pepper. Transfer to plates, top with shaved pecorino cheese and serve.