Pat salmon fillets thoroughly dry with paper towels (essential for crispy skin!). Season both sides with garlic powder, paprika, salt, and black pepper.

Heat olive oil in a large stainless steel or cast iron skillet over medium-high heat until shimmering.

Place salmon skin-side down (or flesh-side down if skinless) and cook undisturbed for 4-5 minutes until a crisp, golden crust forms. Gently flip fillets.

Push salmon slightly to one side of the skillet and tumble in trimmed asparagus spears.

Add butter cubes, minced garlic, and lemon slices to the center of the pan. As butter foams, tilt skillet and use a large spoon to baste the bubbling garlic butter over the salmon and asparagus continuously for 3-4 minutes.

Drizzle fresh lemon juice over everything and cook until salmon reaches an internal temperature of 125-130°F (52-54°C) for medium tender flakiness and asparagus is tender-crisp.

Remove from heat immediately. Scatter fresh chopped dill or parsley over the skillet.

Transfer salmon fillets onto plates alongside roasted asparagus, spoon generous pan butter over top, and serve with extra lemon wedges.