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, up to overnight for deeper flavor development.
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. Fluff with a fork.
04 - Whisk together tahini, yogurt, lemon juice, olive oil, grated garlic, salt, and pepper in a small bowl. Add warm water gradually until desired drizzling consistency is achieved.
05 - Divide fluffy couscous among four serving bowls. Arrange spinach or arugula leaves on top. Add sliced chicken, cherry tomatoes, diced cucumber, red onion slices, Kalamata olives, and feta cheese if using.
06 - Drizzle lemon-tahini sauce generously over each bowl. Garnish with fresh chopped parsley. Serve immediately while chicken is warm and vegetables are crisp.