In a medium bowl, stir together shallot, mustards, mayonnaise, and Creole seasoning. Gently fold in crème fraîche just until combined. Spoon mixture over fish.
Bake until fish is golden brown and flakes easily with a fork, 15 to 20 minutes. Transfer sauce to a bowl, and whisk until smooth. Increase oven temperature to broil.
Line a rimmed baking sheet with foil. Place asparagus in a single layer on prepared pan. Drizzle with oil, and sprinkle with salt.
Broil until browned and just tender, 5 to 7 minutes. Serve fish with asparagus and sauce.
Notes
*We used Blue Plate Mayonnaise and Tony Chachere’s Original Creole Seasoning.
Recipe by Louisiana Cookin' at https://louisianacookin.com/mustard-roasted-mahi-mahi/