Preheat the oven to 400°F (200°C). Gather ingredients and tools.
Mix together the olive oil, garlic, lemon juice, oregano, salt, and pepper to create the marinade.
Add chicken to the marinade, coating well, and let sit for 10 minutes or marinate for up to 2 hours in the fridge.
Place chicken on a baking sheet and bake for 20–25 minutes or until cooked through, checking for an internal temperature of 165°F (74°C).
Cook quinoa or brown rice according to package instructions, and steam broccoli until tender but bright green (about 4–6 minutes).
Assemble meal prep bowls with quinoa or rice, sliced chicken, broccoli, cherry tomatoes, and spinach. Optionally drizzle with more lemon juice or olive oil.
Notes
Marinate chicken for better flavor. Store in airtight containers for up to 4 days. Add fresh spinach and tomatoes after reheating for best texture.