01 - In a mixing bowl, combine olive oil, lemon juice and zest, minced garlic, chopped parsley, oregano, thyme, salt, and black pepper. Add chicken breasts, ensure even coating, cover, and refrigerate for at least 15 minutes or up to overnight.
02 - While chicken marinates, in a medium saucepan bring water or low-sodium chicken broth to a boil. Stir in rinsed quinoa, reduce heat to low, cover, and simmer for 15 minutes or until liquid is absorbed. Remove from heat, fluff with a fork, and cool completely.
03 - Preheat grill or grill pan over medium-high heat. Cook chicken breasts for 6 to 7 minutes per side, or until the internal temperature reaches 165°F and juices run clear. Rest for 5 minutes before slicing.
04 - In a large mixing bowl, combine cooled quinoa, halved cherry tomatoes, diced cucumber, finely chopped red onion, crumbled feta (if using), chopped parsley, and chopped fresh mint.
05 - In a small bowl, whisk together olive oil, lemon juice, Dijon mustard, minced garlic, honey, salt, and black pepper until fully emulsified.
06 - Pour dressing over the quinoa mixture and toss gently to coat all ingredients evenly.
07 - Top the salad with sliced grilled chicken. Serve immediately or chill for later.