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, chop the broccoli into florets, and slice the bell pepper into strips.
Place the vegetables on the baking sheet, drizzle with 0.5 tbsp of avocado oil, and sprinkle with half of the sea salt and dried oregano.
Roast the vegetables in the oven for 20 to 25 minutes, tossing halfway through, until the sweet potatoes are tender and the broccoli edges are crispy.
While vegetables roast, season the chicken breast on both sides with the remaining sea salt and black pepper.
Heat the remaining 0.5 tbsp of avocado oil in a large skillet over medium-high heat.
Place the chicken in the hot skillet and sear for 6 to 8 minutes per side until the internal temperature reaches 165°F and the exterior is golden brown.
During the last minute of cooking, add the minced garlic and lemon juice to the skillet, spooning the juices over the chicken.
Serve the pan-seared chicken immediately alongside the roasted vegetable medley.