Preheat the oven to 450 degrees F. Season with kosher salt and black pepper. Line a baking sheet with parchment paper. Place salmon, skin side down to baking sheet. Brush with Dijon, and sprinkle dill.
Thinly slice the potatoes (I leave the skins on - remember, we're lazy for this meal!) and place in a bowl with the asparagus and lemon juice. Drizzle with the melted ghee, butter or olive oil, season with salt and pepper and toss to coat. Scatter the vegetables on the sheet pan as evenly as possible.
Bake the salmon and vegetables for 20-22 minutes. Salmon will be flaky, and potatoes crispy when done.