In a medium saucepan, combine 4 cups of water with the farro. Bring to a boil over high heat. Cover and simmer over medium-low heat until the farro is almost tender, about 20 minutes. Add 1 1/2 teaspoons of the salt and simmer until the farro is tender, about 10 minutes longer. Drain well. Transfer to a large bowl and let cool.
Meanwhile, bring a medium pot of salted water to a boil over high heat. Add the green beans and stir. Cook for 2 minutes. Transfer the cooked green beans to a bowl of ice water and let cool for 2 minutes. Drain the green beans.
Once the farro has cooled add the green beans, olives, red pepper, Parmesan, and chives. Stir to combine. In a small bowl mix together the sherry vinegar, olive oil, mustard, pepper, and the remaining 1/2 teaspoon salt. Stir to combine. Pour the sherry vinaigrette over the farro salad. Toss to combine and serve.