Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Peel and cube the sweet potato into half-inch pieces, then toss them on the baking sheet with 0.5 teaspoons of olive oil, garlic powder, and half of the sea salt.
Roast the sweet potatoes for 15 minutes, then remove the tray and add the trimmed asparagus spears, tossing them in the residual oil.
Return the tray to the oven and roast for an additional 10 minutes until the potatoes are tender and the asparagus is crisp-tender.
While the vegetables finish roasting, pat the salmon fillet dry with a paper towel and season both sides with the remaining sea salt and black pepper.
Heat the remaining 0.5 teaspoons of olive oil in a non-stick skillet over medium-high heat until shimmering.
Place the salmon in the skillet and sear for 4 to 5 minutes until the skin is golden and crispy, then flip and cook for 2 to 3 minutes until the fish is just opaque.
Plate the seared salmon alongside the roasted vegetables and drizzle the entire dish with fresh lemon juice before serving.