Preheat oven to 350 degrees.
Add salmon and asparagus to sheetpan, spreading out so nothing is too crowded.
In a small bowl, combine oil, lemon juice, and garlic and mix well.
Drizzle oil, lemon juice, and garlic mixture over salmon and asparagus.
Layer lemon on top.
Season well with salt and pepper.
Bake 15-20 minutes, until salmon is opaque and asparagus is soft.
Serve immediately, either on its own, or alongside roasted potatoes, rice, or a nice salad.