Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Place the halved Brussels sprouts, chopped red bell pepper, and cubed sweet potato on the baking sheet.
Drizzle the vegetables with 0.5 tbsp of olive oil and sprinkle with half of the sea salt and black pepper.
Roast the vegetables for 20 to 25 minutes, tossing halfway through, until they are tender and beautifully caramelized.
While the vegetables roast, season the chicken breast evenly with garlic powder, dried oregano, and the remaining salt and pepper.
Heat the remaining 0.5 tbsp of olive oil in a stainless steel or cast-iron skillet over medium-high heat.
Sear the chicken for 6 to 8 minutes per side until the exterior is golden brown and the internal temperature reaches 165°F.
Remove the chicken from the skillet and let it rest on a cutting board for 3 minutes to keep it juicy before slicing.
Plate the sliced chicken alongside the roasted vegetables and drizzle with fresh lemon juice for a bright, zesty finish.