01 - In a mixing bowl, whisk together olive oil, lemon juice and zest, garlic, parsley, oregano, thyme, salt, and black pepper. Add chicken breasts, coat thoroughly, cover, and refrigerate to marinate for at least 15 minutes or up to overnight.
02 - While the chicken marinates, bring water or chicken broth to a boil in a medium saucepan. Stir in quinoa, reduce heat, cover, and simmer for 15 minutes or until liquid is absorbed. Remove from heat, fluff the quinoa with a fork, and allow to cool.
03 - Preheat grill or grill pan to medium-high heat. Remove chicken from marinade. Grill for 6 to 7 minutes per side, or until internal temperature reaches 165°F and juices run clear. Allow chicken to rest for 5 minutes before slicing.
04 - In a large bowl, gently combine cooled quinoa, cherry tomatoes, cucumber, red onion, feta cheese if using, parsley, and mint.
05 - In a small bowl, whisk together olive oil, lemon juice, Dijon mustard, minced garlic, honey, salt, and pepper until well emulsified.
06 - Drizzle dressing over salad ingredients and toss to coat evenly.
07 - Arrange sliced grilled chicken atop the quinoa salad. Serve immediately or chill for later.