Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Snap the woody ends off the asparagus spears and place them on one side of the baking sheet.
Drizzle the asparagus with olive oil and season with a pinch of the sea salt and black pepper, tossing to coat evenly.
Pat the salmon fillet dry with a paper towel and place it on the other side of the baking sheet.
Brush the top of the salmon evenly with the Dijon mustard to create a binder for the crust.
In a small bowl, combine the almond flour, dried parsley, garlic powder, and the remaining salt and pepper.
Press the almond flour mixture firmly onto the top of the salmon fillet to form an even crust.
Roast in the center of the oven for 12 to 15 minutes, or until the salmon flakes easily with a fork and the asparagus is tender-crisp.
Remove from the oven and serve immediately with a fresh squeeze of lemon juice over the fish and vegetables.