Cook the farro according to the directions on the package. Set aside and allow the farro to cool.
Meanwhile, preheat the oven to 425 degrees F.
Place the carrots and brussels sprouts on a large baking sheet. Toss with olive oil, salt, and pepper and distribute the vegetables evenly on the baking sheet.
Roast for 20 minutes, flipping halfway through. Remove the partially-roasted vegetables from the oven and toss them with the maple syrup. Continue roasting for 10-15 minutes, or until the vegtables are caramelized. Remove them from the oven and allow them to cool slightly.
While the vegetables are roasting, make the dressing. Vigorously whisk together the lemon juice, mustard olive oil, maple syrup, salt, and pepper.
In a large bowl, toss together the farro, chopped greens, and roasted vegetables. Drizzle the dressing over the salad and toss until it evenly coats the salad. Serve warm or cold.