01 - Whisk together olive oil, minced garlic, ground cumin, smoked paprika, dried oregano, ground coriander, salt, black pepper, and lemon juice in a bowl. Add chicken breasts and coat thoroughly. Refrigerate for at least 15 minutes or overnight for deeper flavor.
02 - Heat a grill pan or skillet over medium-high heat. Cook marinated chicken breasts for 5-6 minutes per side until golden brown and internal temperature reaches 165°F. Let rest for 5 minutes, then slice into strips.
03 - Bring chicken broth or water to a boil in a saucepan. Stir in couscous, cover tightly, and remove from heat. Let stand for 5 minutes until liquid is absorbed, then fluff with a fork.
04 - Whisk together tahini, yogurt, lemon juice, olive oil, grated garlic, salt, and pepper in a small bowl. Gradually add warm water, 1 tablespoon at a time, until desired drizzling consistency is achieved.
05 - Divide fluffed couscous among four bowls. Arrange spinach or arugula on top, followed by sliced chicken, cherry tomatoes, cucumber, red onion, Kalamata olives, and feta cheese if using.
06 - Drizzle lemon-tahini sauce over each bowl. Garnish with fresh chopped parsley. Serve immediately while chicken is warm.