Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Dice the sweet potato and red bell pepper into 1-inch cubes, and chop the broccoli into uniform bite-sized florets.
Place the vegetables on the baking sheet and toss with half of the olive oil, half of the sea salt, half of the black pepper, and all of the dried oregano.
Roast the vegetables in the oven for 20-25 minutes, tossing halfway through, until the sweet potatoes are tender and slightly caramelized.
While the vegetables roast, season the chicken breast on both sides with garlic powder and the remaining sea salt and black pepper.
Heat the remaining olive oil in a heavy-bottomed skillet over medium-high heat.
Place the chicken in the skillet and sear for 6-7 minutes per side until the exterior is golden brown and the internal temperature reaches 165°F.
Remove the chicken from the pan and let it rest for 5 minutes before slicing it against the grain and serving with the roasted vegetables.