Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Slice the red bell pepper and zucchini into bite-sized pieces and combine them with the broccoli florets in a large bowl.
Drizzle the vegetables with half of the olive oil and season with half of the sea salt and black pepper, tossing well to coat.
Spread the vegetables in a single layer on the prepared baking sheet and roast for 18-20 minutes until the edges are caramelized and tender.
While the vegetables roast, season the chicken breast on both sides with the dried thyme, dried rosemary, and the remaining salt and pepper.
Heat the remaining olive oil in a heavy-bottomed skillet over medium-high heat.
Place the chicken in the skillet and sear for 6-7 minutes per side, or until the internal temperature reaches 165°F and the exterior is golden and crispy.
In the final minute of cooking, add the minced garlic and lemon juice to the pan, spooning the juices over the chicken to infuse it with flavor.
Remove the chicken from the pan and let it rest for 3 minutes before serving alongside the roasted vegetable medley.