Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Peel and dice the sweet potato into 1/2-inch cubes, then place them in a medium mixing bowl.
Toss the sweet potato cubes with the avocado oil, garlic powder, and half of the sea salt until well coated.
Spread the sweet potatoes in a single layer on the prepared baking sheet and roast for 15 minutes.
While the potatoes roast, trim the woody ends off the asparagus and lightly season them.
Add the asparagus to the baking sheet with the potatoes and roast for an additional 10-12 minutes until the vegetables are tender.
Pat the salmon fillet dry with a paper towel and season both sides with the remaining sea salt and black pepper.
Heat the ghee in a medium cast-iron or non-stick skillet over medium-high heat until shimmering.
Place the salmon in the pan, skin-side down, and sear for 4-5 minutes without moving it to ensure a crispy texture.
Carefully flip the salmon and cook for another 2-3 minutes until the fish is opaque and flakes easily.
Remove from heat, drizzle with fresh lemon juice, and serve immediately alongside the roasted vegetables.