Slice the chicken breast into thin bite-sized strips and place them in a medium mixing bowl.
Whisk together the olive oil, lemon juice, garlic powder, cumin, coriander, paprika, salt, and pepper, then pour over the chicken to coat evenly.
Heat a large non-stick skillet over medium-high heat and add the marinated chicken, searing for 6-8 minutes until golden brown and cooked through.
While the chicken is cooking, dice the cucumber, halve the cherry tomatoes, and finely mince the red onion to create a fresh salad garnish.
In a small ramekin, stir together the plain Greek yogurt and dried oregano until smooth.
Assemble the meal prep bowl by placing the cooked brown rice at the bottom and topping it with the spiced chicken strips.
Add the cucumber and tomato salad to the side and finish with a dollop of the herb-infused yogurt sauce.