Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Cut the chicken breast into even 1-inch cubes and place them in a large mixing bowl.
Chop the red bell pepper, zucchini, and red onion into bite-sized pieces, then add them to the bowl with the chicken and chickpeas.
In a small jar or bowl, whisk together the harissa paste, extra virgin olive oil, lemon juice, sea salt, and black pepper until smooth.
Pour the harissa marinade over the chicken and vegetable mixture, tossing thoroughly to ensure every piece is well-coated.
Spread the mixture in a single, even layer onto the prepared baking sheet to ensure even roasting.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred edges.
Remove from the oven and garnish with freshly chopped parsley before serving hot.