Preheat your oven to 400°F and line a rimmed baking sheet with parchment paper.
Trim the woody ends off the asparagus spears and toss them on the baking sheet with half of the olive oil, half the sea salt, and half the black pepper.
Spread the asparagus in a single layer and roast for 10-12 minutes until tender-crisp and slightly charred.
While the asparagus roasts, pat the salmon fillet completely dry with a paper towel to ensure a crispy sear.
Season the salmon on both sides with the remaining sea salt, black pepper, and garlic powder.
Heat the remaining olive oil in a stainless steel or cast-iron skillet over medium-high heat until shimmering.
Place the salmon skin-side down in the skillet and press gently with a spatula for 30 seconds to prevent curling.
Cook for 4-5 minutes until the skin is crispy and the flesh is cooked halfway up the side, then flip and cook for another 2-3 minutes.
Remove from heat and serve the salmon alongside the roasted asparagus with a fresh squeeze of lemon juice over everything.