Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Cut the chicken breast into 1-inch bite-sized cubes.
In a mixing bowl, whisk together the harissa paste, olive oil, lemon juice, sea salt, and black pepper.
Add the chicken cubes and drained chickpeas to the bowl, tossing thoroughly until every piece is coated in the spicy harissa marinade.
Spread the chicken and chickpeas in a single layer on the prepared baking sheet and roast for 15-18 minutes until the chicken is cooked through.
While the chicken roasts, steam the broccoli florets for 4-5 minutes until they are tender-crisp and bright green.
Warm the pre-cooked brown rice in a small pan or microwave until steaming.
Assemble the bowl by placing the rice at the base, then topping with the roasted harissa chicken, chickpeas, and steamed broccoli.
Garnish with freshly chopped parsley and an extra squeeze of lemon if desired.