1. Preparation
Preheat your oven to 400°F (200°C).
Rinse the fish fillets under cold water and pat them dry with paper towels.
Season both sides of the fish fillets with salt and pepper.
Place the hazelnuts in a food processor and pulse until finely chopped, but not powdered.
Transfer the chopped hazelnuts to a shallow dish.
In another shallow dish, whisk together the eggs and Dijon mustard until well combined.
Prepare a baking sheet by lining it with parchment paper.
2. Coating the Fish
Dip each fish fillet into the egg mixture, ensuring it's fully coated.
Allow any excess egg to drip off, then place the fillet into the dish with the chopped hazelnuts.
Press the hazelnuts onto the fish to ensure an even and thick coating. Repeat for all fillets.
Place the coated fillets on the prepared baking sheet.
3. Cooking
Drizzle a little olive oil over the coated fish fillets.
Bake in the preheated oven for 15-20 minutes, or until the fish is cooked through and the hazelnut crust is golden brown.
Check for doneness by flaking the fish with a fork; it should be opaque and easily flake apart.
4. Serving
Remove the fish from the oven and let it rest for a minute.
Serve the hazelnut crusted fish immediately with a garnish of fresh parsley and lemon wedges on the side.