Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Dice the zucchini, red bell pepper, and red onion into uniform bite-sized pieces to ensure even cooking.
Cut the chicken breast into 1-inch cubes and place them on the baking sheet along with the chopped vegetables.
In a small bowl, whisk together the extra virgin olive oil, minced garlic, dried rosemary, dried thyme, sea salt, and black pepper.
Drizzle the herb-infused oil over the chicken and vegetables, then toss with your hands or a spatula until every piece is well-coated.
Spread the mixture out into a single layer on the pan, ensuring nothing is overcrowded so the vegetables roast rather than steam.
Roast in 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 immediately drizzle with fresh lemon juice to brighten the flavors before serving.