How to Make It
Heat oven to 400° F. Cook the farro in a large pot of boiling salted water until tender, 20 to 30 minutes. Drain and transfer to a large bowl.
Meanwhile, heat 1 tablespoon of the oil in a large skillet over medium-high heat. Season the chicken with the lemon zest and ¼ teaspoon each salt and pepper. Brown the chicken in batches, 4 to 6 minutes per side. Transfer to a rimmed baking sheet; reserve the skillet. Roast the chicken until a thermometer inserted in the thickest part of a thigh registers 165° F, 18 to 22 minutes.
Add the asparagus to the drippings in the skillet and cook over medium-high heat, tossing occasionally, until just tender, 3 to 5 minutes. Transfer the asparagus to the bowl with the farro, along with the radishes, Feta, lemon juice, mint leaves, the remaining tablespoon of oil, and ¼ teaspoon each salt and pepper; toss to combine. Serve the chicken with the farro salad.