Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Trim the tough, woody ends off the asparagus and spread the spears in a single layer on one side of the prepared baking sheet.
Drizzle 0.5 tbsp of olive oil over the asparagus and sprinkle with 0.125 tsp of sea salt and 0.125 tsp of black pepper, tossing to coat evenly.
In a small bowl, whisk together the almond flour, dried parsley, garlic powder, and the remaining salt and pepper until well combined.
Place the salmon fillet on the other side of the baking sheet, then brush the top surface with the Dijon mustard and the remaining 0.25 tbsp of olive oil.
Spoon the almond flour mixture over the salmon and press it down firmly with your fingers to create a thick, even 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.
Remove from the oven and serve immediately with a fresh squeeze of lemon juice over both the salmon and the roasted asparagus.