Preheat your oven to 400°F and line a baking sheet with parchment paper.
Peel and cube the sweet potato, then place in a pot of boiling water for 12-15 minutes until fork-tender.
Trim the woody ends off the asparagus and toss with half of the olive oil, salt, and pepper.
Spread the asparagus on the baking sheet and roast for 10-12 minutes until tender but still crisp.
Pat the salmon fillet dry with a paper towel and season both sides with garlic powder, salt, and pepper.
Heat the remaining olive oil in a non-stick skillet over medium-high heat.
Place the salmon in the pan and sear for 4-5 minutes on the first side, then flip and cook for another 2-3 minutes until the center is just opaque.
Drain the sweet potatoes and mash them thoroughly, adding a tablespoon of hot water if needed to reach a creamy consistency.
Plate the salmon alongside the sweet potato mash and roasted asparagus, finishing the dish with a fresh squeeze of lemon juice.