In a large zip bag, combine olive oil, garlic, lemon juice, red wine vinegar, oregano, Greek yogurt, salt, and pepper. Massage to mix.

Add chicken into the bag, ensure full coverage, and marinate for at least 20 minutes or up to 12 hours.

Drain the chicken and discard marinade. Heat a skillet over medium-high heat with a little olive oil.

Cook chicken for about 3-4 minutes per side until internal temperature reaches 165 degrees F. Remove and let cool, then cut into bite-sized pieces.

Meanwhile, prepare cucumber salad by tossing chopped cucumbers with lemon juice, olive oil, vinegar, garlic, and oregano. Set aside.

Make tzatziki by combining Greek yogurt, diced cucumber, garlic, dill, lemon juice, lemon zest, and season with salt, pepper, and mint if desired.

Refrigerate tzatziki and cucumber salad while assembling bowls.

Cook brown rice as per package directions. Divide into meal prep containers, then top with sliced chicken, cucumber salad, cherry tomatoes, and red onion slices.

Add a dollop of tzatziki to each bowl. Cover and refrigerate for 3-5 days. Serve cold.