Marinate the chicken: In a large bowl, whisk olive oil, lemon zest and juice, garlic, oregano, thyme, cumin (if using), salt, and pepper.
Add chicken and toss to coat. Cover and refrigerate at least 30 minutes or up to 8 hours.
Start the rice: Rinse rice under cold water until the water runs mostly clear. In a pot, heat olive oil over medium, add rice, and toast 1–2 minutes.
Add broth, salt, and lemon zest. Bring to a boil, then reduce to low, cover, and cook 15–18 minutes for white rice (40–45 for brown). Rest 10 minutes, then fluff.
Prep the veggie mix: In a bowl, combine cucumber, tomatoes, red onion, olives, dill or parsley, olive oil, red wine vinegar, and a pinch of salt and pepper.
Toss gently. Set aside.
Cook the chicken: Heat a large skillet or grill pan over medium-high. Lightly oil.
Remove chicken from marinade (let excess drip off) and cook 5–7 minutes per side, depending on thickness, until the center hits 165°F (74°C). Rest 5 minutes, then slice.
Make the quick yogurt sauce (optional): Stir Greek yogurt with lemon juice, grated garlic, and a pinch of salt. Thin with a teaspoon of water if needed.
Assemble the meal prep bowls: Divide rice among 5 containers.
Top with sliced chicken, a scoop of the veggie mix, and a sprinkle of feta. Add lemon wedges and a small container of yogurt sauce if using.
Cool before sealing: Let containers sit uncovered 15–20 minutes to release steam. Then seal and refrigerate.