Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Place the broccoli florets, chopped red bell pepper, and sliced red onion on the baking sheet.
Drizzle the vegetables with half of the olive oil and season with half of the sea salt and all of the dried oregano; toss well to coat.
Roast the vegetables in the oven for 15-20 minutes until they are tender and show slight charred edges.
While the vegetables roast, season the chicken breast on both sides with the remaining sea salt and black pepper.
Heat the remaining olive oil in a medium skillet over medium-high heat.
Place the chicken in the skillet and sear for 5-7 minutes per side, or until the internal temperature reaches 165°F.
During the last minute of searing, add the minced garlic to the pan and stir until fragrant, being careful not to burn it.
Remove the chicken from the heat and let it rest for 3 minutes before slicing.
Plate the chicken alongside the roasted vegetables and finish everything with a fresh drizzle of lemon juice.