Marinate the chicken: In a bowl, whisk olive oil, lemon juice and zest, garlic, oregano, cumin, smoked paprika, salt, and pepper. Add chicken and toss to coat. Marinate at least 20 minutes, up to 6 hours in the fridge.
Cook your grain base: Cook brown rice, quinoa, or farro according to package directions.
Fluff with a fork and season with a pinch of salt. Let it cool slightly before assembling bowls.
Make the salad: Combine tomatoes, cucumber, red onion, and parsley. Toss with red wine vinegar, olive oil, salt, and pepper.
Set aside to absorb the dressing.
Cook the chicken: Heat a grill pan or skillet over medium-high. Add a drizzle of oil if needed. Cook chicken 5–7 minutes per side, depending on thickness, until the internal temperature reaches 165°F (74°C).
Rest 5 minutes, then slice.
Whisk the lemon-tahini (optional): Stir tahini, lemon juice, water, salt, and garlic powder until smooth. Add more water slowly if you prefer a thinner drizzle.
Assemble the bowls: Divide grains among 4 meal prep containers. Add sliced chicken, a scoop of cucumber-tomato salad, a dollop of hummus, olives, and feta.
Tuck in a lemon wedge. Add greens if using.
Dress before eating: If using the tahini drizzle or tzatziki, pack it in a small container and add just before eating to keep textures fresh.