Marinate the chicken. In a bowl, combine lemon zest and juice, olive oil, minced garlic, oregano, cumin, smoked paprika, salt, and pepper. Add chicken and toss to coat.
Cover and refrigerate for at least 30 minutes, or up to 8 hours for deeper flavor.
Cook the quinoa. Rinse quinoa under cold water until it runs clear. Add to a pot with broth and a pinch of salt. Bring to a boil, then reduce heat, cover, and simmer for 15 minutes.
Turn off heat and let it steam, covered, for 5 minutes. Fluff with a fork and stir in olive oil, parsley, and mint.
Make the sauce. In a small bowl, whisk Greek yogurt, tahini, garlic, lemon juice, salt, and pepper. Add water a little at a time until it’s spoonable but not runny.
Taste and adjust salt or lemon.
Prep the veggies. Dice the cucumber, halve the tomatoes, and slice the red onion thin. Pat olives dry and crumble the feta. Keep each in separate bowls if meal prepping.
Cook the chicken. Heat a large skillet or grill pan over medium-high.
Add a light drizzle of oil if needed. Cook chicken 5–6 minutes per side, until browned and cooked through (internal temp 165°F/74°C). Rest 5 minutes, then slice or dice.
Assemble the bowls. Add a generous scoop of quinoa to each bowl.
Top with chicken, cucumber, tomatoes, red onion, olives, and feta. Spoon over the yogurt-tahini sauce. Finish with a squeeze of lemon and a sprinkle of red pepper flakes if you like heat.
Optional toast. For extra crunch, toast pine nuts in a dry skillet for 2–3 minutes until golden, then scatter on top.