Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Trim the tough, woody ends off the asparagus spears and place them on one side of the prepared baking sheet.
Drizzle the asparagus with olive oil and sprinkle with half of the sea salt and black pepper, tossing to coat evenly.
Place the salmon fillet on the other side of the baking sheet and brush the top surface with the Dijon mustard.
In a small bowl, combine the almond flour, garlic powder, dried parsley, and the remaining sea salt and black pepper.
Press the almond flour mixture firmly onto the top of the salmon fillet to create an even, thick crust.
Bake for 12 to 15 minutes, or until the salmon is opaque and flakes easily with a fork and the crust is golden brown.
Remove from the oven and squeeze the fresh lemon juice over both the salmon and the roasted asparagus before serving.