Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Peel the sweet potato and cut it into small half-inch cubes to ensure they cook at the same rate as the other ingredients.
Place the cubed sweet potatoes and broccoli florets on the prepared sheet pan, drizzle with half of the olive oil, and sprinkle with a pinch of sea salt and black pepper.
Toss the vegetables to coat evenly and spread them out in a single layer, then roast in the oven for 10 minutes.
While the vegetables are roasting, pat the salmon fillet dry with a paper towel and season the top with the remaining olive oil, dried oregano, garlic powder, sea salt, and black pepper.
Remove the pan from the oven, push the vegetables to the sides to make room in the center, and place the salmon fillet on the pan.
Return the pan to the oven and roast for an additional 12 to 15 minutes, or until the salmon flakes easily with a fork and the sweet potatoes are tender and caramelized.
Remove from the oven, drizzle the fresh lemon juice over the salmon and vegetables, and serve immediately while hot.