Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Peel and dice the sweet potato into 1/2-inch cubes, and chop the broccoli and red bell pepper into bite-sized pieces.
Place the vegetables on the prepared baking sheet and toss with 0.5 tablespoon of olive oil, half of the sea salt, and half of the black pepper.
Roast the vegetables in the oven for 20 to 25 minutes, tossing halfway through, until the sweet potatoes are tender and lightly browned.
While the vegetables roast, pat the chicken breast dry and season both sides evenly with the dried oregano, garlic powder, and the remaining salt and pepper.
Heat the remaining 0.5 tablespoon of olive oil in an oven-safe skillet over medium-high heat.
Sear the chicken for 3 to 4 minutes on one side until a golden crust forms, then flip the breast and transfer the skillet to the oven.
Bake the chicken for 8 to 10 minutes or until the internal temperature reaches 165°F (74°C).
Allow the chicken to rest for 5 minutes before slicing it and serving alongside the roasted vegetable medley.