Ingredients:

  • 4 (6 oz) portions White Fish Fillets (Cod, Haddock, or Halibut), skin removed
  • 1 tsp Salt, divided
  • 1/2 tsp Black Pepper, divided
  • 1 Tbsp Unsalted Butter (for sautéing spinach)
  • 1 clove Fresh Garlic, minced
  • 10 oz Fresh Spinach, washed and thoroughly dried
  • 3 Tbsp Unsalted Butter (for the roux)
  • 3 Tbsp All-Purpose Flour
  • 2 cups Whole Milk
  • Pinch Freshly Grated Nutmeg
  • 1 tsp Dijon Mustard
  • 1/2 cup Gruyère or Mature Cheddar Cheese, grated
  • 1/4 cup Parmesan Cheese, finely grated
  • Salt and White Pepper, to taste

Instructions:

  1. Preheat oven to 400°F (200°C). Season the fish fillets generously with salt and pepper.
  2. Melt 1 Tbsp of butter in a large skillet over medium heat. Add the minced garlic and sauté for 30 seconds until fragrant.
  3. Add the spinach in batches until completely wilted down. Cook until all excess moisture has evaporated. Remove from heat.
  4. Place the cooked spinach in a fine-mesh sieve or wrap in a clean kitchen towel and thoroughly squeeze out all remaining liquid. (This prevents the sauce from becoming watery).
  5. Spread the dried, seasoned spinach evenly across the bottom of a 9x13 inch baking dish. Place the seasoned fish fillets neatly on top of the spinach base.
  6. To make the Mornay sauce, melt the remaining 3 Tbsp of butter in a heavy-bottomed saucepan over medium heat. Whisk in the 3 Tbsp of flour constantly to form a smooth roux. Cook the roux for 1-2 minutes until it smells faintly nutty, but do not let it brown.
  7. Gradually pour the whole milk into the roux, whisking continuously to prevent lumps. Bring the mixture to a gentle simmer, stirring frequently.
  8. Reduce the heat to low and cook for 5–7 minutes until the sauce coats the back of a spoon thickly (this is the Béchamel base).
  9. Remove the Béchamel from the heat. Stir in the nutmeg, Dijon mustard, salt, and white pepper. Gradually stir in the grated Gruyère or Cheddar until completely melted and smooth. Taste and adjust seasoning.
  10. Pour the rich Mornay sauce evenly over the fish fillets, ensuring they are completely covered.
  11. Sprinkle the top generously with the grated Parmesan cheese.
  12. Bake for 15–18 minutes, or until the fish is flaky and cooked through (internal temperature should reach 145°F / 63°C) and the sauce is bubbling hot and beautifully golden brown on top.
  13. Allow the Florentine to rest for 5 minutes before serving.