1. Steam the fish for 10 minutes.
2. Meanwhile, prepare the béchamel sauce: melt the butter in a saucepan, add the flour and whisk together. Gradually add the milk while whisking until the mixture is smooth.
3. Cook, stirring constantly, until the sauce thickens. Season with salt, pepper, and nutmeg.
4. Flake the cod fillets and mix them into the béchamel sauce.
5. Spread a thin layer of béchamel sauce in an ovenproof dish, then cover with lasagna sheets. Repeat the process, finishing with a layer of béchamel sauce.
6. In a bowl, mix together the breadcrumbs, Parmesan cheese, almond powder, pine nuts, salt, and pepper.
7. Sprinkle the mixture over the dish and bake for 30 minutes.