Preheat the oven to 200°C. Peel the sweet potato and cut into cubes. Spread them on a baking sheet with parchment paper, drizzle with half the olive oil and a pinch of salt, and roast for twenty minutes.
Break off the woody ends of the asparagus. After the first twenty minutes, add them to the sweet potato on the sheet, sprinkle with finely chopped garlic and roast for another ten minutes.
Pat the salmon dry and season with salt and pepper. Heat the remaining oil in a frying pan and cook the salmon skin-side down for about four minutes, flip it over and cook for another two minutes. Drizzle with lemon juice, sprinkle with dill and serve with the roasted vegetables. Salmon is rich in omega-3 fatty acids.