Lamb Chops with Farro, Arugula, and Lemon-Thyme Vinaigrette

The ever-expanding range of instant grains on the market, such as the farro used here, makes it easier to incorporate whole grains into everyday meals. Feel free to replace them with brown rice if you can't find farro.
Preheat a grill pan over medium-high heat. Brush with cooking spray. Sprinkle the lamb with 1/4 teaspoon salt and 1/4 teaspoon pepper. Transfer to the skillet; cook for 5 minutes on each side. Remove from the pan; let stand for 5 minutes.Preheat the farro according to the instructions on the package. Drain and place on a baking sheet to allow them to cool slightly.Combine the remaining 1/4 teaspoon salt, remaining 1/4 teaspoon pepper, zest, and the next 6 ingredients (with thyme added) in a small bowl.Combine the farro and arugula in a bowl. Add half of the dressing; stir to coat. Spread the farro evenly over 4 serving plates; place 2 lamb chops on each plate. Pour the remaining sauce over the lamb.