Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Chop the broccoli, red bell pepper, and zucchini into uniform bite-sized pieces to ensure even cooking.
Place the vegetables on the baking sheet, drizzle with half of the olive oil, and season with a pinch of sea salt and black pepper.
Toss the vegetables well and roast in the oven for 18-20 minutes until they are tender and show slight caramelized edges.
While the vegetables roast, season the chicken breast on both sides with the remaining sea salt, black pepper, and dried oregano.
Heat the remaining olive oil in a cast-iron or heavy skillet over medium-high heat.
Place the chicken in the pan and sear for 6-7 minutes per side until the exterior is golden brown and the internal temperature reaches 165°F.
During the last minute of searing, add the minced garlic to the pan to infuse the chicken with aromatic flavor without burning the garlic.
Remove the chicken from the pan and let it rest for 3 minutes to keep the juices intact.
Serve the chicken alongside the roasted vegetables and finish with a fresh squeeze of lemon juice over the entire plate.