Preheat the oven to 425°F.
Peel (or scrub) the sweet potato and cut it into 1/2-inch cubes. Toss the cubes with half the olive oil, a pinch of salt, pepper, and garlic powder.
Spread the sweet potato cubes on a baking sheet in a single layer. Roast in the oven for 20-25 minutes or until tender and slightly caramelized, tossing halfway through.
While the sweet potatoes are roasting, pat the salmon fillet dry with paper towels.
Season the salmon on both sides with a pinch of salt, pepper, and a light dusting of garlic powder. Optionally, gently press a few rosemary leaves onto the surface for added aroma.
Heat a non-stick skillet over medium-high heat and add the remaining olive oil.
Place the salmon skin-side down (if applicable) in the hot skillet and cook for about 3-4 minutes until the skin is crispy and golden. Flip and cook for an additional 2-3 minutes, until the salmon is just cooked through.
Plate the salmon alongside the roasted sweet potatoes and serve immediately.