Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Dice the sweet potato, bell peppers, and red onion into uniform bite-sized pieces.
Place the vegetables on the baking sheet and toss with half of the olive oil, the ground cumin, and half of the sea salt and black pepper.
Roast the vegetables for 20-25 minutes, tossing halfway through, until the sweet potatoes are tender and the edges are golden brown.
While the vegetables roast, whisk together the lime juice, chopped fresh cilantro, garlic powder, and the remaining olive oil in a small bowl to create a marinade.
Season the chicken breast with the remaining salt and pepper, then brush with half of the cilantro-lime marinade.
Heat a non-stick skillet over medium-high heat and sear the chicken for 6-7 minutes per side until the internal temperature reaches 165°F.
Rest the chicken for 3 minutes, then slice and drizzle with the remaining fresh marinade before serving alongside the roasted vegetable medley.