Marinate the chicken. In a bowl, mix olive oil, lemon zest and juice, garlic, oregano, cumin, smoked paprika, salt, and pepper. Add the chicken and toss to coat.
Let it sit for at least 20 minutes (or up to 8 hours in the fridge).
Cook your grain base. Prepare quinoa, farro, rice, or couscous according to package directions. Fluff with a fork and season with a pinch of salt and a splash of olive oil for extra flavor.
Make the dressing. Whisk tahini, lemon juice, olive oil, grated garlic, honey, and salt. Add water, 1 tablespoon at a time, until smooth and drizzleable.
Taste and adjust salt and lemon.
Prep the veggies. Halve tomatoes, dice cucumber and bell pepper, thinly slice red onion, and chop herbs. If the onion is sharp, soak the slices in cold water for 10 minutes, then drain.
Cook the chicken. Heat a large skillet over medium-high. Add a drizzle of olive oil.
Sear chicken strips 4–6 minutes total, turning once, until browned and cooked through. Rest for 5 minutes, then slice into bite-size pieces.
Assemble the bowls. Add a bed of grains and greens. Top with chicken, tomatoes, cucumber, red onion, bell pepper, olives, and feta.
Add a spoonful of hummus and avocado slices if using.
Finish with dressing. Drizzle the tahini-lemon dressing over the top. Sprinkle with chopped parsley or mint. Add optional roasted chickpeas or pine nuts for crunch.
Taste and tweak. Add a squeeze of lemon, a pinch of salt, or extra dressing as needed.
Serve warm or at room temperature.