Preheat the oven to 400°F.
Peel and cube the sweet potato into evenly-sized chunks. Toss them lightly with half a teaspoon of olive oil, salt, and pepper.
Spread the sweet potato onto a baking sheet and roast in the oven for about 20-25 minutes, until tender and lightly browned.
While the sweet potato is roasting, trim the asparagus by snapping off the woody ends and lightly drizzle with a little olive oil, salt, and pepper.
Heat a non-stick skillet over medium-high heat. Season the salmon fillet on both sides with salt and pepper.
Place the salmon fillet in the skillet skin-side down (if applicable) and sear for 3-4 minutes. Flip and sear the other side for an additional 3-4 minutes until cooked through but still moist.
As the salmon finishes, quickly sauté the asparagus in the same skillet for 2-3 minutes if a slightly warmer vegetable is preferred, or serve them fresh.
Drizzle the salmon with lemon juice just before serving, and plate alongside the roasted sweet potato and asparagus.