Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Pat the chicken breast dry with paper towels and cut into 1-inch bite-sized pieces.
Slice the carrots into thin rounds and the zucchini into half-moons so they cook at the same rate as the broccoli.
In a large mixing bowl, combine the chicken, broccoli, carrots, and zucchini.
Mince the garlic and add it to the bowl along with the olive oil, rosemary, thyme, sea salt, and black pepper.
Toss everything thoroughly until the chicken and vegetables are evenly coated in the oil and spices.
Spread the mixture onto the prepared sheet pan in a single layer, ensuring the pieces are not touching to allow for proper roasting.
Roast in the center of the oven for 18 to 22 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender.
Remove from the oven and immediately drizzle with fresh lemon juice to brighten the flavors before serving.