Step 1: Preheat and prep the pan: Set the oven to 200°C (400°F) and preheat. Line the sheet pan with parchment and brush lightly with oil to prevent sticking. This step makes cleanup almost zero.
Step 2: Arrange the vegetables: Lay asparagus on one side of the pan, drizzle with a little olive oil, and add black pepper and sliced garlic. Toss so every spear is coated. A single layer is what gives the veggies char instead of steaming.
Step 3: Add the salmon: Place the salmon skin-side down on the other side of the pan. Brush the top with olive oil, then season with salt, black pepper, and dill. Lay two lemon slices on top of each fillet.
Step 4: Roast: Roast at 200°C for 12–14 minutes. At 12 minutes the edges turn opaque while the center is still slightly translucent — that is the sweet spot; for well done, go to 14 minutes. When the center reaches 63°C/145°F (the FDA minimum safe temperature for fish), the salmon is fully cooked. Pregnant women, people with weakened immune systems, and children should eat it cooked to fully done.
Step 5: Rest and serve: Out of the oven, squeeze fresh lemon over the top and rest 2 minutes so the fish firms up. Serve straight from the pan with rice or a salad.