Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Chop the broccoli into bite-sized florets, slice the bell pepper into strips, and coin the carrots.
Place the vegetables on the prepared baking sheet and toss with 0.5 tbsp of olive oil, 0.125 tsp sea salt, and 0.125 tsp black pepper.
Roast the vegetables for 18-20 minutes, tossing halfway through, until they are tender and have developed golden, caramelized edges.
While vegetables roast, season the chicken breast evenly with dried oregano, garlic powder, and the remaining salt and pepper.
Heat the remaining 0.5 tbsp of olive oil in a heavy-bottomed skillet over medium-high heat.
Sear the chicken for 6-7 minutes per side until the exterior is crispy and the internal temperature reaches 165°F.
Remove from heat, drizzle with fresh lemon juice, and serve the chicken immediately alongside the roasted vegetables.