Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
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 season with a pinch of the sea salt and black pepper, tossing to coat evenly.
Pat the salmon fillet dry with a paper towel to ensure the crust adheres, then place it on the other side of the baking sheet.
Spread the Dijon mustard in a thin, even layer over the top surface of the salmon.
In a small bowl, combine the almond flour, garlic powder, dried parsley, lemon zest, and the remaining salt and pepper.
Carefully press the almond-herb mixture onto the mustard-coated salmon to create a uniform crust.
Roast in the center of the oven for 12 to 15 minutes, or until the salmon is opaque and flakes easily with a fork and the asparagus is tender-crisp.
Serve immediately, optionally garnished with a fresh squeeze of lemon juice.