This spinach stuffed flounder is made with tender fish fillets rolled around a savory spinach, onion and Parmesan filling. The rolls are topped with seasoned breadcrumbs, baked with white wine and finished with fresh parsley. It looks a little fancy, but it’s actually a really easy dinner.
I love this recipe when I want something light without feeling like I’m just eating a plain piece of fish and calling it a day. The spinach filling keeps the flounder moist, while the Parmesan and breadcrumbs give the top a little texture.
This is basically a stuffed version of flounder Florentine. Serve it with roasted vegetables, potatoes, rice or a simple salad for an easy dinner that still feels special.
Jump to:
- Why You’ll Love This Recipe
- What Is Flounder Florentine?
- Spinach Stuffed Flounder Ingredients
- How to Make Spinach Stuffed Flounder
- Top Tip
- Substitutions
- Spinach Stuffed Flounder Variations
- What to Serve with Spinach Stuffed Flounder
- Make Ahead
- How to Store Stuffed Flounder
- Frequently Asked Questions
- Spinach Stuffed Flounder
- Food safety
Why You’ll Love This Recipe
- It’s ready in about 35 minutes. The spinach filling comes together quickly, and thin flounder fillets only need about 12–15 minutes in the oven.
- The filling keeps the fish moist. Flounder is delicate and can dry out quickly. Rolling it around the spinach filling helps protect the fish while it cooks.
- It uses simple ingredients. Spinach, onion, Parmesan, breadcrumbs and white wine do most of the work here.
- It looks more complicated than it is. Stuffing and rolling the fish takes a few extra minutes, but the technique is very easy. No tiny chef hat required.
- It’s easy to serve. Pair it with vegetables for a lighter meal or add potatoes, rice or crusty bread when you want something more substantial.
What Is Flounder Florentine?
“Florentine” usually describes a dish prepared with spinach. You’ll see the term used for fish, chicken, eggs and pasta, sometimes with a cream sauce.
This version skips the heavy cream sauce. Instead, the spinach is cooked with onion, mixed with Parmesan and breadcrumbs, and rolled directly inside the flounder. White wine in the baking dish adds moisture and creates a light sauce underneath the fish.
The result is a lighter baked flounder Florentine with plenty of spinach and a crisp Parmesan-breadcrumb topping.
If you prefer brighter, lemony flavors, try my Flounder Piccata next. It’s made with lemon, capers, butter and white wine.
Spinach Stuffed Flounder Ingredients
You’ll only need a few simple ingredients to make this recipe. The exact measurements are listed in the recipe card below. Here’s an overview of what you’ll need:
Flounder: Look for four similarly sized fillets so they cook at the same rate. Flounder is thin and delicate, which makes it easy to roll. Sole is the closest substitute.
Baby spinach: Fresh baby spinach wilts quickly and has tender stems, so there’s very little prep involved. One pound looks like a ridiculous amount until it cooks down. Spinach loves drama like that.
Onion: Finely chopped onion adds flavor without making the filling chunky. Yellow, white or sweet onion will all work.
Parmesan: Parmesan seasons the filling and helps the topping turn golden. Freshly grated Parmesan melts better than the shelf-stable kind.
Italian-seasoned breadcrumbs: The breadcrumbs absorb extra moisture in the filling and create a lightly crisp topping. Regular breadcrumbs also work; just add a pinch of dried Italian seasoning.
Dry white wine: Use a dry wine such as Pinot Grigio or Sauvignon Blanc. You only need ¼ cup, so use something you would actually drink. If you prefer not to cook with alcohol, use seafood, chicken or vegetable broth.
Extra-virgin olive oil: Part of the oil is used to cook the onion and spinach, and the rest is drizzled over the fish before baking.
Fresh parsley: Parsley adds freshness and color at the end. A squeeze of lemon would also be really good here.
Salt and black pepper: Season the filling and both sides of the fish, but go lightly at first because Parmesan and seasoned breadcrumbs already contain salt.
See recipe card for quantities.
How to Make Spinach Stuffed Flounder
Preheat the oven to 400°F and position a rack in the upper third of the oven. Lightly grease an 11-by-8-inch baking dish.
Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the onion and cook for 4–5 minutes, stirring occasionally, until softened. Add the spinach a few handfuls at a time. Stir as it wilts and continue adding spinach until it all fits in the skillet. Cook for another 2–3 minutes, just until tender.
Transfer the spinach mixture to a colander and let it cool slightly. Press firmly with a spatula or the back of a spoon to remove as much liquid as possible. Transfer the drained spinach to a bowl. If the leaves are still very large, give the mixture a rough chop. Stir in 2 tablespoons of Parmesan and 1 tablespoon of breadcrumbs. Season lightly with salt and pepper.
Pat the flounder fillets dry and season both sides with salt and black pepper.
Divide the spinach filling among the fillets, placing it near the center of each piece. Fold both ends of the fillet over the filling to form a loose roll. Arrange the rolls seam-side down in the prepared baking dish.
If you have extra spinach filling, spoon it around the fish. Absolutely no reason to waste it.
Pour the white wine around and lightly over the stuffed fillets.
Pour the white wine around and lightly over the stuffed fillets.
Combine the remaining Parmesan and breadcrumbs, then sprinkle the mixture over the fish. Drizzle with the remaining ½ tablespoon of olive oil.
Bake for 12–15 minutes, until the fish is opaque and flakes easily with a fork. The exact time will depend on the thickness of the fillets.
Garnish with chopped parsley and serve immediately.
Top Tip
Squeeze as much liquid as possible from the cooked spinach. This is the difference between a flavorful filling that stays inside the fish and a watery baking dish.
Also, start checking the flounder at 12 minutes. It is a thin fish and can go from tender to overcooked pretty quickly.
Substitutions
Flounder: Sole is the easiest substitute because it is similarly thin and easy to roll. Thin tilapia fillets can also work, although they may need a few extra minutes in the oven.
Fresh spinach: You can use frozen chopped spinach. Thaw it completely and squeeze it extremely well before mixing it with the onion, Parmesan and breadcrumbs. Frozen spinach holds a surprising amount of water.
Parmesan: Pecorino Romano works, but it is saltier, so reduce the added salt. Grana Padano is another good option.
Italian breadcrumbs: Use plain breadcrumbs with ¼ teaspoon of Italian seasoning. Panko will give you a coarser, crunchier topping.
White wine: Substitute an equal amount of seafood, chicken or vegetable broth. Add a small squeeze of lemon to replace some of the wine’s acidity.
Onion: Shallot is a great substitute and has a slightly milder flavor.
Spinach Stuffed Flounder Variations
Add garlic: Cook one or two minced garlic cloves with the onion during the final minute.
Make it lemony: Add lemon zest to the spinach filling and serve the finished fish with lemon wedges.
Add more cheese: Mix a few tablespoons of shredded mozzarella into the spinach for a cheesier filling. Don’t add too much or the rolls may be difficult to close.
Use a crispier topping: Replace the regular breadcrumbs on top with panko. Broil the fish for about one minute after baking if it needs more color, but watch it closely.
Add heat: Mix red pepper flakes into the spinach or sprinkle them over the finished fish.
Make individual rolls: If your fillets are very large, cut them lengthwise into narrower pieces and make smaller flounder rolls. Begin checking them a few minutes earlier.
What to Serve with Spinach Stuffed Flounder
This stuffed flounder with spinach already includes a vegetable, but I still like adding a simple side to make it a complete meal.
My Dijon Brussels Sprouts are a really good choice if you want something crisp and savory. The mustard adds enough acidity to balance the Parmesan filling.
For something lighter, serve it with my Shaved Fennel Salad with Parmesan. The crunchy fennel and red wine vinaigrette work especially well with delicate fish.
You could also make my Sazón Grilled Vegetables or Grilled Romaine with Feta. Add rice, roasted baby potatoes or crusty bread if you want something to soak up the white wine juices.
If you enjoy baked fish with white wine, my White Wine Salmon is another easy dinner to save for later. This Pan-Seared Halibut with Lemon Butter Caper Sauce is made with capers, lemon and parsley.
Speaking of saving recipes, I keep my favorites written on cards so I can find them without scrolling through my phone with fish-covered hands. My Cilantro Parsley Recipe Card Box Set is made for exactly that.
Make Ahead
You can prepare the spinach filling up to one day in advance. Let it cool completely, cover it and refrigerate it separately from the fish.
You can also assemble the flounder rolls several hours ahead. Arrange them in the baking dish, cover tightly and refrigerate. Wait to add the wine, breadcrumb topping and olive oil until just before baking.
Take the baking dish out of the refrigerator while the oven preheats. Cold fish may need an additional minute or two in the oven.
How to Store Stuffed Flounder
Refrigerator: Store leftover flounder in an airtight container for up to two days.
Reheating: Reheat it in a covered baking dish at 300°F until just warmed through. Add a splash of broth or water to the dish to keep the fish from drying out. The microwave works in a hurry, but use short intervals at reduced power.
Freezer: I don’t recommend freezing the cooked rolls. The texture of both the fish and spinach filling can become watery after thawing.
Frequently Asked Questions
Can I use frozen spinach?
Yes. Thaw the spinach completely and squeeze out as much liquid as possible. You’ll need approximately 10 ounces of frozen chopped spinach to replace one pound of fresh spinach.
Can I prepare the stuffed flounder ahead of time?
Yes. Assemble the rolls a few hours ahead and keep them covered in the refrigerator. Add the wine, breadcrumbs, Parmesan and olive oil immediately before baking.
How do I keep the flounder rolls closed?
Place them seam-side down in the baking dish. That is usually enough to hold them together. If your fillets are especially small or slippery, secure each roll with a toothpick and remove it before serving.
How do I know when flounder is cooked?
The flesh should be opaque and should flake easily when pressed with a fork. A thermometer inserted into the thickest part should register 145°F. Start checking at 12 minutes because thin fillets cook quickly.
Can I make this recipe without wine?
Absolutely. Replace the wine with seafood, chicken or vegetable broth. Add a squeeze of fresh lemon for acidity.
Is spinach stuffed flounder gluten-free?
Not as written because the filling and topping contain breadcrumbs. Use gluten-free seasoned breadcrumbs to make it gluten-free, and confirm that the Parmesan and broth are also certified gluten-free if necessary.
Spinach Stuffed Flounder
- Total Time: 35 minutes
- Yield: 4 servings 1x
Description
This spinach stuffed flounder features tender fish fillets rolled around a savory Parmesan-spinach filling, topped with breadcrumbs and baked with white wine.
Ingredients
- 4 flounder fillets
- 1½ tablespoons extra-virgin olive oil, divided
- 1 small onion, finely chopped
- 1 pound baby spinach, rinsed and thoroughly dried
- 3 tablespoons freshly grated Parmesan cheese, divided
- 3 tablespoons Italian-seasoned breadcrumbs, divided
- ¼ cup dry white wine
- 1 tablespoon chopped fresh parsley
- Salt and freshly ground black pepper, to taste
- Lemon wedges for serving, optional
Instructions
- Preheat the oven to 400°F. Position a rack in the upper third of the oven and lightly grease an 11-by-8-inch baking dish.
- Heat 1 tablespoon olive oil in a large skillet over medium heat. Add the onion and cook for 4–5 minutes, stirring occasionally, until softened.
- Add the spinach a few handfuls at a time, stirring until wilted. Cook for 2–3 minutes, just until tender.
- Transfer the spinach mixture to a colander. Let it cool slightly, then press firmly with a spatula or the back of a spoon to remove as much liquid as possible.
- Transfer the drained spinach to a bowl. Coarsely chop it if needed. Stir in 2 tablespoons Parmesan and 1 tablespoon breadcrumbs. Season lightly with salt and pepper.
- Pat the flounder fillets dry and season both sides with salt and pepper. Divide the spinach filling evenly among the fillets, placing it near the center of each piece.
- Fold both ends of each fillet over the filling to form a loose roll. Arrange the fillets seam-side down in the prepared baking dish. Spoon any extra spinach around the fish.
- Pour the white wine around and lightly over the fillets. Sprinkle with the remaining 1 tablespoon Parmesan and 2 tablespoons breadcrumbs. Drizzle with the remaining ½ tablespoon olive oil.
- Bake for 12–15 minutes, until the fish is opaque and flakes easily with a fork. The internal temperature should reach 145°F.
- Garnish with parsley and serve immediately with lemon wedges, if desired.
Notes
- Drain the spinach very well so the filling and baking dish do not become watery.
- Begin checking the fish at 12 minutes. Thin flounder fillets can overcook quickly.
- Sole is the best substitute for flounder.
- Replace the wine with broth and a squeeze of lemon if needed.
- Prep Time: 15 minutes
- Cook Time: 20 minutes
- Category: Dinner
- Method: Baking
- Cuisine: Italian
Food safety
- Cook to a minimum temperature of 165 °F (74 °C)
- Do not use the same utensils on cooked food, that previously touched raw meat
- Wash hands after touching raw meat
- Don't leave food sitting out at room temperature for extended periods
- Never leave cooking food unattended
- Use oils with high smoking point to avoid harmful compounds
- Always have good ventilation when using a gas stove
Addison Seychelles
I was so shocked at how good this tasted!
Robyn Vig
May I suggest you strain/squeeze your spinach before adding to sauté onion so that you don’t wash away the onion flavor.
Maxine Dubois
Good call!
Linda
Delicious! I did forget the white wine though. I also just placed the spinach mixture on top of each filet instead of stuffing it. Will make again.
Maxine Dubois
so glad you loved it!!