Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Dice the sweet potato into 1/2-inch cubes and chop the broccoli and bell peppers into bite-sized pieces.
Place the vegetables on the prepared baking sheet and toss with 0.5 tbsp of olive oil and half of the salt and pepper.
Roast the vegetables for 20-25 minutes, tossing halfway through, until the sweet potatoes are fork-tender and slightly caramelized.
While the vegetables are roasting, season the chicken breast on both sides with garlic powder, dried oregano, and the remaining salt and pepper.
Heat the remaining 0.5 tbsp of olive oil in a heavy skillet over medium-high heat.
Sear the chicken for 6-7 minutes per side until the exterior is golden-brown and the internal temperature reaches 165°F.
Allow the chicken to rest for 3 minutes before slicing and serving alongside the roasted vegetable medley.