Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper for easier cleanup.
In a small bowl, mix together the olive oil, minced garlic, Italian seasoning, salt, and pepper.
Place the trimmed asparagus on one side of the prepared baking sheet. Drizzle half of the oil mixture over the asparagus and toss to coat evenly. Spread the asparagus into a single layer.
Place the salmon fillets on the other side of the baking sheet. Brush the remaining oil mixture evenly over the tops of the salmon fillets.
Arrange a few thin lemon slices on top of each salmon fillet.
Bake for 12 to 15 minutes, or until the salmon is cooked through and flakes easily with a fork, and the asparagus is tender-crisp. Cooking time depends on the thickness of your salmon.
Remove from the oven. Garnish with fresh chopped parsley before serving immediately.
Notes
If your asparagus spears are very thick, toss them with the oil mixture 5 minutes before adding the salmon to the pan to ensure they cook evenly.
For extra brightness, squeeze fresh lemon juice over the finished dish just before serving.
This recipe works well for meal prepping; divide portions into airtight containers once cooled.