Heat oven to 425°F. On a rimmed baking sheet, toss green beans and 6 sprigs thyme with 1 tablespoon oil and 1/4 teaspoon each, salt and pepper. Nestle artichokes onto pan, cut sides down, and roast on bottom rack in oven until tender and golden brown, about 10 to 12 minutes.
Meanwhile, heat remaining tablespoon oil in an oven-safe skillet on medium. Season chicken with a 1/4 teaspoon each salt and pepper and cook until golden brown on bottom, about 3 to 4 minutes. Flip chicken over and cook 2 minutes more.
Add lemon, cut side down, and remaining 6 thyme sprigs to skillet. Transfer skillet to oven along with vegetables and roast until chicken is cooked through, about 9 minutes more. Serve with artichokes and green beans, plus cooked quinoa seasoned however you like. Yum!