Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Chop the zucchini into half-moons, slice the red bell pepper into thin strips, and cut the red onion into small wedges.
Mince the garlic clove and slice the chicken breast into even, bite-sized strips for quick roasting.
In a large mixing bowl, combine the chicken, zucchini, peppers, and onion.
Drizzle with olive oil and sprinkle with oregano, rosemary, minced garlic, sea salt, and black pepper.
Toss everything together until the chicken and vegetables are evenly coated in the oil and herbs.
Spread the mixture in a single layer on the prepared baking sheet to ensure even browning.
Roast for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender and slightly caramelized.
Remove from the oven and immediately squeeze the fresh lemon juice over the hot pan before serving.