In a large mixing bowl, combine the cubed chicken, 1 tablespoon of olive oil, minced garlic, oregano, salt, pepper, lemon juice, and lemon zest. Toss to coat evenly.
Heat a large non-stick skillet over medium-high heat. Add the chicken and cook for 8 to 10 minutes, stirring occasionally, until the chicken is browned and reaches an internal temperature of 165 degrees Fahrenheit.
In a separate pan over medium heat, sauté the broccoli florets and sliced red onion with the remaining 1 tablespoon of olive oil for 6 to 8 minutes until tender-crisp.
Prepare four meal prep containers. Portion 1/2 cup of cooked brown rice into each container.
Divide the cooked lemon garlic chicken and the sautéed vegetables equally among the four containers.
Allow the meals to cool slightly before sealing and refrigerating for up to 4 days.