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This 20-minute baked flounder recipe is a stand-up weeknight meal that will get your family to eat more fish—even the kids. Flounder is mild in flavor, and when you cover it in a cheesy breadcrumb topping and slide it into the oven, it becomes the kind of thing your family gets excited about.

Flounder fillets with golden crisp top.

If fish has ever felt intimidating—the smell, the texture, the general uncertainty of it all—this baked flounder recipe is where you start. Flounder is a white fish, mild and flaky, with none of that aggressively fishy thing that turns people off. What it does have is good bones (figuratively—it’s actually quite boneless), meaning it takes well to a crispy parmesan and thyme breadcrumb topping that does a lot of the heavy lifting. The whole thing comes together in 20 minutes, which means there’s really no excuse not to make it.

Want more easy fish recipes? My baked Alaska pollock is very similar to this recipe, with a few minor tweaks. This pan-fried flounder is great if you like a nice creamy lemon-caper sauce. And when you’re ready for it, these easy salmon recipes will change the way your family eats fish for good.





Why You’ll Love This Recipe

  • High-protein and pretty filling for a light fish
  • Ready in 20 minutes
  • You probably have most of the ingredients kicking around
  • No greasy fried fish smell or mess

Ingredient Overview

Ingredients for baked flounder au gratin on a dark stone background.

A quick look at the essentials before we dive into the recipe card:

  • Panko: This type of bread crumb is heartier than Italian bread crumbs, so it holds up to moisture without getting soggy and keeps its crispness.
  • Parmesan: Adds a nice cheesy crust and a bit of saltiness.
  • Dried thyme: For a nice herb-y flavor. You could use chopped fresh thyme, or use my homemade Italian seasoning.

Step-by-Step: How to Make Baked Flounder

Salt and pepper-seasoned fish fillets on a parchment-lined baking sheet.

Step 1: Preheat the oven to 400ºF with the rack positioned in the middle.

Step 2: Season the Fish

With a paper towel, gently blot the fillets to remove excess moisture. Then, season both sides of the fillets with sea salt and cracked black pepper and set aside.

Step 3: Make That Tasty Crumb Mixture

In a small bowl, mix together 1 cup of bread crumbs, 2/3 cup of grated parmesan, 1 teaspoon of dried thyme, and about 1/2 teaspoon of sea salt. Once well blended, stir in 1 tablespoon of olive oil. Keep stirring until the bread crumbs are all coated—they’ll become darker in color and have a crumbly texture.

Small bowl of bread crumb and parmesan mixture.

Step 4: Coat the Fish, Then Bake

Sprinkle the bread crumb mixture evenly over the flounder fillets. Gently pat it down with your fingers. Transfer the fish to the oven and bake—thin fillets may be done in 8-10 minutes, while thicker ones can take up to 15-20 minutes. The fish is done when its opaque, flakes easily with a fork, and reaches an internal temperature of 140°F. (You can check this with a meat thermometer.)

Flounder fillets uncooked, covered in bread crumb and parmesan mixture.

Step 5: Garnish & Serve

When done, remove the fish from the oven. Garnish each fillet with finely chopped parsley, and serve with lemon wedges for a nice, refreshing spritz!

Cooked golden crisp flounder au gratin on baking sheet.

Recipe Tip

If by the 10-minute mark your bread crumbs don’t seem to be turning golden, you can switch to the broiler on high for a minute or two. Keep a close eye on them so they don’t burn.

Substitutions & Variations

  • For a buttery flavorSwap the olive oil for 1 tablespoon of melted butter.
  • Garlicky goodness: Use garlic salt in the breadcrumb mixture instead of sea salt.
  • Other white fish fillets: This recipe works with any mild white fish, such as Alaska pollock, tilapia, cod, or halibut. Note that cooking times will vary, depending on the thickness of the fish.
  • Cheese options: Instead of Parmesan, finely grate some Gruyére or sharp cheddar.

Storage & Reheating

  • Fridge: Leftover flounder will keep in the fridge in an airtight container for up to 2 days, but the quality of texture will decrease. Thin white fish fillets don’t hold up as well once refrigerated.
  • Reheating: Place the fish in the microwave and reheat in 15-second increments until warmed through.
Flounder au gratin on a plate with rice and green beans.

Frequently Asked Questions

What is the best way to eat flounder?

Pan-fried or baked is best, since this is a delicate fish. You could run into problems with it on the grill. When it comes to flavor, less is more. Think fresh flavors that sing, like lemon, garlic, and herbs.

What is the best way to bake flounder?

My go-to approach is high heat and a quick trip through the oven. This keeps the flounder moist instead of sad and rubbery. From there, you want something on top that does the work: a Parmesan-panko crust that gets genuinely crispy, like in this recipe; a lemon-butter-garlic situation that soaks right in.

Should I bake fish in the oven covered or uncovered?

This depends. In this recipe, the uncovered flounder is sufficiently covered by the bread crumb topping to keep it from drying out, and you want that bread crumb coating to turn golden and crisp. If covered, it will steam and get mushy. If you’re baking flounder without a bread-crumb topping, you’ll want to cover it for the first part of cooking, then uncover it for the last 3-5 minutes to get a golden finish.

Why is my baked flounder mushy?

This happens if you don’t pat your fish fillets with paper towels to remove excess moisture before cooking, or if you go too heavy on the sauce.

4.97 from 28 votes

Crispy Parmesan Baked Flounder Recipe

This 20-minute baked flounder recipe is a stand-up weeknight meal that will get your family to eat more fish—even the kids. Flounder is mild in flavor, and when you cover it in a cheesy breadcrumb topping and slide it into the oven, it becomes the kind of thing your family gets excited about.
Prep Time: 10 minutes
Cook Time: 10 minutes
Total Time: 20 minutes
Servings: 4 servings
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Ingredients 

  • 4 flounder fillets, No flounder? You could use any white fish for this recipe.
  • 2 TBSP extra virgin olive oil, divided, *See notes
  • 1 cup panko breadcrumbs
  • 2/3 cups freshly grated Parmigiano Reggiano cheese
  • 1/2 tsp sea salt, more to taste
  • A few grinds of cracked black pepper
  • 1 tsp dried thyme, You could also use a dried Italian herb mix
  • Chopped fresh parsley, for garnish
  • Lemon wedges, for serving

Instructions 

  • Preheat the oven to 400º F with the rack positioned in the middle.
  • Gently blot the fillets with a paper towel to remove excess moisture. Season both sides of the fillets with a bit of sea salt and cracked black pepper; set them aside.
  • In a small mixing bowl, add 1 cup of bread crumbs, 2/3 cup of grated parmesan, 1 teaspoon of dried thyme, and 1/2 teaspoon of sea salt. Mix it well, then stir in 1 tablespoon of olive oil. Keep stirring until the bread crumbs are all coated. They will appear darker in color and have a crumbly texture.
  • Sprinkle the bread crumb mixture evenly over the flounder fillets. Gently pat the bread crumbs into the fillets with your fingers so they stay in place.
  • Transfer the fish to the oven and bake. Thin fillets may be done in 8-10 minutes, while thicker ones can take up to 15-20 minutes. The fish is done when its opaque, flakes easily with a fork, and reaches an internal temperature of 140°F, which can be verified with a meat thermometer.
  • When the fish is done, remove it from oven and garnish each fillet with finely chopped parsley. Serve with lemon wedges for a nice refreshing spritz!

Notes

  1. For a nice buttery crumb, you could melt 1 TBSP of butter and stir it into the bread crumbs in place of the olive oil.
  2. If by the 10-minute mark your bread crumbs don’t seem to be turning a golden color, you can then switch to the broiler, on high, for just a minute or two. Just keep a close eye on them so they don’t burn.

Nutrition

Serving: 1serving | Calories: 302kcal | Carbohydrates: 10g | Protein: 32g | Fat: 13g | Saturated Fat: 4g | Polyunsaturated Fat: 1g
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More Easy Weeknight Fish Recipes

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48 Comments

  1. 5 stars
    We love this recipe! It’s so easy that even my wife, who doesn’t like to cook, will make it if I need her to do dinner one night (I’m usually the dinner guy), and she never minds because it’s so straightforward and it always turns out. This is the only fish our kids will eat. Thanks for a great family-friendly recipe!

  2. 5 stars
    This recipe was so good, even picky eaters liked it. It had so much flavor and the crunchy topping was a big hit. Definitely going to be making this a regular meal choice. We had fresh lemons off the tree and that just added to the flavor, thanks for a great recipe!

  3. 5 stars
    I made this last evening and it was amazing!  I put some pesto on the flounder before adding the crumb mixture and what a winner!  My hubby kept telling me how good it was and it made my day!  Thank you for a great recipe that we will use often!

  4. 5 stars
    Oh yum! I love how easily this flounder comes together for those new to working with fish. It looks fantastic, especially with that crust!