Preheat grill to medium-high heat. In a bowl, mix olive oil, lemon juice, lemon zest, garlic, oregano, thyme, salt, and pepper. Coat chicken with half the mixture and let marinate for 10 minutes.
Cook quinoa according to package instructions. Toss vegetables with remaining marinade and spread on a baking sheet. Roast at 400°F for 20 minutes.
Grill chicken for 6-7 minutes per side or until internal temperature reaches 165°F. Serve with quinoa and roasted vegetables.