Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Peel and cube the sweet potato into 1/2-inch pieces, and slice the red bell pepper into strips.
In a large bowl, toss the sweet potato, broccoli florets, and bell pepper with 0.5 tablespoons of olive oil, half the sea salt, and half the black pepper.
Spread the vegetables in a single layer on the prepared baking sheet and roast for 20-25 minutes until the potatoes are fork-tender and slightly caramelized.
While the vegetables roast, season the chicken breast on both sides with garlic powder, dried oregano, and the remaining salt and pepper.
Heat the remaining 0.5 tablespoons of olive oil in a cast-iron or stainless steel skillet over medium-high heat.
Place the chicken in the hot skillet and sear for 5-7 minutes per side, or until the internal temperature reaches 165°F and the crust is golden brown.
Remove the chicken from the pan and let it rest for 3-5 minutes before slicing against the grain.
Plate the sliced chicken alongside the roasted vegetables and finish with a fresh squeeze of lemon juice over everything.