Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Dice the sweet potato into half-inch cubes and slice the bell pepper into thin strips.
Place the sweet potatoes, broccoli florets, and bell peppers on the baking sheet, drizzle with half of the avocado oil, and season with a pinch of sea salt and pepper.
Roast the vegetables for 20-25 minutes, tossing halfway through, until the sweet potatoes are fork-tender and the broccoli edges are slightly charred.
While the vegetables roast, season the chicken breast evenly on both sides with garlic powder, smoked paprika, sea salt, and black pepper.
Heat the remaining avocado oil in a large skillet over medium-high heat.
Add the chicken to the hot 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 to lock in the juices before slicing.
Plate the sliced chicken alongside the roasted vegetables and finish with a fresh squeeze of lemon juice over everything.