Cut open the salmon fillet without cutting and opening it. Season with salt and curry.
Sweat the shallots and garlic in the butter, let the spinach collapse, season with salt and pepper and drain well on a sieve. Top the salmon fillet with Gouda cheese, cover with spinach leaves, cover with Gouda cheese and fold the salmon fillet up. Bread with flour, eggs and breadcrumbs and bake on both sides, depending on the thickness, for 2-5 minutes in hot clarified butter until golden brown.