Preheat your oven to 400°F and line a rimmed baking sheet with parchment paper for easy cleanup.
Snap the woody ends off the asparagus and toss the spears on the baking sheet with half of the avocado oil, minced garlic, and a pinch of sea salt and black pepper.
Roast the asparagus for 10 to 12 minutes until the tips are slightly charred and the stalks are tender.
While the vegetables roast, pat the salmon fillet very dry with a paper towel to ensure a perfect sear and season both sides with the remaining salt and pepper.
Heat the rest of the avocado oil in a heavy-bottomed skillet over medium-high heat until it begins to shimmer.
Carefully place the salmon in the pan skin-side down and press firmly with a flexible spatula for 10 seconds to prevent curling.
Sear the salmon undisturbed for 4 to 5 minutes until the skin is golden and crispy, then flip and cook for another 2 minutes for a medium-rare center.
Transfer the salmon to a plate with the roasted asparagus and finish with a bright squeeze of fresh lemon juice.