Ingredients:

  • 10 oz block Frozen Chopped Spinach (thawed and thoroughly squeezed dry)
  • ½ cup Whole Milk Ricotta Cheese
  • ¼ cup Grated Parmesan Cheese
  • 1 Large Egg Yolk
  • 1 clove Garlic, finely minced
  • ⅛ teaspoon freshly grated Nutmeg
  • Salt and Freshly Ground Black Pepper, to taste
  • 4 Flounder Fillets (approx. 5–6 oz each)
  • 1 tablespoon Olive Oil (or melted unsalted butter, for greasing)
  • 2 tablespoons Panko Breadcrumbs (optional topping)
  • ½ cup Dry White Wine (e.g., Sauvignon Blanc)
  • 1 small Shallot, finely minced
  • 4 tablespoons Unsalted Butter (cold, cubed)
  • 1 tablespoon Fresh Lemon Juice
  • 1 tablespoon Fresh Parsley, chopped
  • White Pepper, to taste

Instructions:

  1. Dry the Spinach: Place the thawed spinach in a clean tea towel and wring out all excess water. This is crucial—if the filling is wet, it will leak and make the fish soggy.
  2. Combine Filling Ingredients: In a mixing bowl, combine the dried spinach, ricotta, Parmesan, egg yolk, minced garlic, nutmeg, salt, and pepper. Mix thoroughly until the mixture is thick and homogeneous.
  3. Prep the Fish: Pat the flounder fillets completely dry with paper towels. Season the fillets lightly on both sides with salt and pepper.
  4. Spread the Filling: Lay one fillet flat. Spread approximately ¼ of the filling mixture evenly over the fillet, leaving about a ½-inch border on all sides.
  5. Roll and Secure: Starting from the short end, tightly roll the fillet into a cylinder. If the fillet is large, secure the roll with a piece of kitchen twine or a small wooden skewer inserted horizontally.
  6. Prepare for Baking: Lightly grease a 9x13 inch baking dish with olive oil or melted butter. Place the rolled fillets seam-side down in the dish, ensuring they are slightly separated. Brush the tops of the rolls lightly with oil/butter and sprinkle with Panko breadcrumbs for texture, if desired.
  7. Bake: Preheat the oven to 400°F (200°C). Bake the stuffed flounder for 18–22 minutes. The fish is done when it is opaque throughout and flakes easily with a fork (internal temperature should reach 145°F).
  8. Reduce Aromatics: While the fish is baking, add the white wine and minced shallot to a small saucepan. Bring to a simmer over medium heat and reduce until only about 2 tablespoons of liquid remain.
  9. Emulsify the Butter (The Magic): Remove the pan from the heat. Begin whisking vigorously. Add the cold, cubed butter one piece at a time, whisking constantly until each piece is fully incorporated before adding the next. This creates a smooth, emulsified sauce (a beurre monté). Do not let the sauce boil once the butter is added.
  10. Finish Seasoning: Whisk in the lemon juice, salt, and white pepper. Keep the sauce warm, but off the direct heat.
  11. Plating and Serving: Carefully remove the flounder rolls from the oven and remove any twine or skewers. Let rest for 2 minutes. Spoon a generous ladle of the warm lemon-butter sauce onto the plate, place a flounder roll on top, and garnish with fresh chopped parsley.