Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Dice the chicken breast, zucchini, red bell pepper, and red onion into uniform 1-inch pieces.
Place the chicken and vegetables on the baking sheet and toss with 0.25 tablespoons of olive oil, sea salt, black pepper, and dried oregano.
Roast in the oven for 18-20 minutes until the chicken is fully cooked and the vegetables are tender and slightly charred.
While the tray roasts, bring a small pot of water to a boil and cook the pearl couscous for 8-10 minutes until al dente, then drain.
In a large mixing bowl, whisk together the remaining 0.25 tablespoons of olive oil and the lemon juice.
Add the cooked couscous, roasted chicken, and vegetables to the bowl, toss with fresh parsley to combine, and serve warm.