Preheat oven to 450 degrees. Arrange salmon in a shallow baking pan. Season with salt and pepper. Roast until no longer pink in the middle and flaky, 10 to 13 minutes. Using a flat spatula, remove fillets, leaving skin on the baking sheet.
In a small bowl, whisk together lime juice, soy sauce, and sugar; fold in cilantro. Spoon sauce over fish, and serve with asparagus.