Baked flounder is a one-pot, restaurant-worthy meal you can make in about 20 minutes! Fish fillets are seasoned, then baked with vegetables and a bold lemony Mediterranean sauce and finished with Parmesan!
What I Love About this Flounder Recipe
When I created this baked flounder recipe with vegetables, I wanted something that felt fancy, but didn’t take all evening to make. Flounder is a white saltwater fish with a mild flavor and a delicate, flaky texture. It is a low-mercury flatfish that is easy to work with and cooks quickly because it’s so thin.
I whipped up a bold, lemony sauce with garlic, extra-virgin olive oil, sweet paprika, and oregano to infuse the fish and vegetables with flavor while keeping it moist as it cooks. No dry fish here! The finishing sprinkle of nutty Parmesan cheese adds a textural element and a little salty bite! It’s better than any baked fish you’ll have at a fancy restaurant, I promise!
Ingredients for baked flounder
With just a few ingredients, you’ll have the perfect baked flounder in no time! Here’s what you’ll need for this easy fish recipe:
- Flounder fillets: You’ll need 1 1/4-pounds of fish fillets.
- Vegetables: Zucchini and red onion, both cut into 1/2-inch half-moon slices.
- Garlic: 3 minced garlic cloves add the perfect garlicky kick to this baked fish recipe.
- Spices: Dried oregano, sweet paprika, and cumin add warmth and some earthiness.
- Lemons: You’ll need fresh lemon juice to brighten and lift the earthy flavors, as well as lemon wedges for serving.
- Extra virgin olive oil: 1/4 to 1/3 cup EVOO is needed, so it’s best to use quality olive oil, like our mild but flavorful Italian Nocellara extra virgin olive oil.
- Parmesan cheese: I find that freshly grated parmesan is more robust than the pre-grated kinds, so I highly recommend buying a block and grating it yourself.
How to Make Baked Flounder
This is one of my favorite flounder fillet recipes because it requires minimal prep and is ready in about 20 minutes. Simply season the fish and vegetables, make the sauce, and bake!
- Make the sauce. Whisk together 3 cloves minced garlic, 2 teaspoons dried oregano, 1/2 teaspoon each sweet paprika and cumin, the juice of 2 lemons, and about 1/4 cup extra virgin olive oil in a small bowl.
- Season the fish and vegetables. Pat 1 1/4 pounds of flounder fillets dry, and season on both sides with kosher salt and black pepper. Arrange the fish in a large oven-safe dish, and add 2 medium zucchini and 1 small red onion, both halved and sliced into half moons. Season the veggies with salt and pepper as well. Pour the sauce over the fish and vegetables to coat.
- Bake the flounder and vegetables. Place the baking dish in a 350°F heated oven for 7 to 10 minutes. Remove the baking dish from the oven and sprinkle 1/2 cup grated Parmesan over the flounder and vegetables. Place the dish back in the oven and bake for 5 minutes more until the flounder is flaky and the cheese has melted a bit. Remove from the oven and serve hot.
Flounder Tips
- Don’t overcook the fish! Flounder fillets overcook quickly because they are so thin. I recommend checking for doneness before the 10-minute mark. If you find the fish is cooking quickly, add the Parmesan cheese sooner so you still have a little time for it to melt.
- Flounder Substitutions: If you can’t find flounder fillets for this recipe, branzino, halibut, trout, or sole are good substitutes. You want thin fish filets for this recipe. Both flounder and Dover sole are usually sold in thin filets, so both types of fish cook at similar speeds, so you won’t have to adjust the cooking time too much.
- How do you know when flounder is cooked through? Fish is cooked when it has reached an internal temperature of 140-145°F. Keep in mind the fish will continue to cook after being removed from the oven, so it’s better to take it out closer to 140°F and let the carryover cooking finish the job. Check the temperature after about 7 minutes.
- If you don’t have a thermometer, look at the color and texture of the fish. The fish will turn from opaque to white and flake easily with a fork.
Swaps and Substitutions
- Can I use frozen flounder? Yes! Frozen flounder works great in this recipe; just thaw it in the refrigerator 24 hours before you make this recipe.
- If you have to swap a thicker fish, any mild white fish filets will work in this recipe, like cod, snapper, or even haddock. You may need to increase the cooking time by 5 or 10 minutes, depending upon the thickness of the fish you choose. Always check the internal temperature, which should be between 140-145°F when ready to remove from the oven.
- Swap the vegetables: If you don’t have zucchini, use yellow summer squash, or other tender vegetables like asparagus, green beans, or colorful bell peppers.
What to Serve with Baked Flounder
The beauty of a mild-flavored fish like flounder is that it goes with many different things. We’ve already included zucchini and onions with the baked fish, but there are many other sides to choose from.
- Try my herby boiled potatoes or smashed potatoes.
- For less starchy vegetables, try roasted broccoli, Greek green bean salad, or this asparagus salad.
- Add a grain or pasta like pearl couscous, basmati rice, or this easy lemon pasta.
Leftovers and storage
Leftover cooked flounder will keep in an airtight container in the fridge for up to 2 days. I prefer to eat leftover fish at room temperature so it doesn’t become overcooked with reheating. You can toss everything in a skillet set over medium-low heat for a few minutes until just heated through.
Baked Fish Recipes to Try Next
Fish and Seafood
Stuffed Flounder with Tomatoes, Roasted Red Peppers, and Olives
Fish and Seafood
Poached Flounder with Sweet Corn Salsa
Fish and Seafood
Baked Trout with Lemon, Garlic, and Fresh Herbs
Ingredients
- 1 1/4 pounds flounder fillets, sole fillet will also work
- 2 medium zucchini, halved and cut into ½-inch slices (half moons)
- 1 small red onion, halved and cut into ½-inch slices (half moons)
- kosher salt
- black pepper
- 3 garlic cloves, minced
- 2 teaspoons dried oregano
- 1/2 teaspoon sweet paprika
- 1/2 teaspoon cumin
- Juice of 2 lemons, plus more lemon wedges for serving
- 1/4 cup to 1/3 cup extra virgin olive oil
- 1/2 cup grated Parmesan cheese
Instructions
- Heat the oven to 350°F.
- Make the sauce: In a small mixing bowl, combine garlic, spices, lemon juice, and olive oil. Whisk to combine.
- Prepare the fish: Pat the fish dry with paper towels and season well with kosher salt and black pepper on both sides. Arrange the fish in a large baking dish. Add the zucchini and onions to it and season with salt and pepper. Pour the sauce all over the fish and vegetables.
- Bake: Bake in the heated oven for 7 to 10 minutes, then carefully remove the pan and sprinkle the grated parmesan all over the fish and vegetables. Return the pan to the oven and bake for another 3 to 5 minutes or so until the fish is flaky and the cheese has melted some. (Flounder fillets are thin and should not take too long to cook. Be careful not to overcook them.)
Notes
- Substitutes for flounder: Branzino, halibut, sole, cod, trout, snapper, or haddock — any mild white fish would work. Just be sure to use thin fish filets.
- Tip for success: Flounder fillets cook very quickly, so check after it has been baking for 7 minutes or so. If you find that the fish is cooking faster than expected, add the Parmesan sooner to give it some time to melt.
- Can you use frozen flounder in this recipe? Yes, just be sure to thaw it overnight in the fridge. And pat it dry to remove excess moisture.
- Serve baked flounder with: Try my herby boiled potatoes or smashed potatoes. For a green side, try roasted broccoli, Greek green bean salad, or this asparagus salad.
- Leftovers and storage: Store leftovers in an airtight container in the fridge for up to 2 days. I prefer to eat leftover fish at room temperature. But you can add everything to a skillet over medium-low heat for a few minutes until just heated through.
- Visit our shop to browse our all-natural and organic spices (like the paprika and cumin used in this recipe), olive oils, and much more!
Nutrition
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Oh my goodness, this is delicious. I made it with flounder, and followed the recipe exactly. My husband loves to fish and he comes home with fish 3-4 days a week. I am ok with fish once in a while but by midsummer I am really really sick of fish and look for recipes to use it and possibly even mask it a bit…lol. This is VERY good and I made it a few days ago, here he comes again with more fish….gonna make it again tonight! This time I’m going to grate the zucchini so it will be as soft as I want it to be. Thanks very much!
Haha! You’re a good sport to support your hubby’s fishing hobby. We have so many other great fish recipes on the site. Hope you check out some others :).
I made this tonight for dinner. My child who loves fish wouldn’t eat it. He said it had too much lemon and it made him not like the taste, and I have to agree. The veggies need to be cooked before hand, because the 10mins in the oven barely warm them through appropriately… and I cut them smaller than directed. I ended up removing the fish, and letting the veggies cook for longer in the oven.
Over all, it was a bit of a disappointment… The only thing that saved dinner was the fact that I made some cacio e pepe pasta and it was neutral enough to counteract the lemon
Hi, Marcie! I’m Summer from The Mediterranean Dish. Thanks for your comment. We will evaluate the recipe. I’m sorry it wasn’t a hit for you and your family, but glad the cacio e pepe was.
This was a total winner! I loved it, my family loved it, just a great dish. I did it on a whim as I had defrosted the flounder and had to cook it. I googled for an easy recipe and yours came up. I had everything but the zucchini but was delicious just the same. I book marked your website and am looking forward to trying some of your other dishes. Thank you 🙂
I have never been much for baked fish. This was really good the sauce is the key. Its also quick and easy. I will be making it again.
I really want to try this recipe, but based on some of the negative reviews, I’m a bit apprehensive. I have had such success with Suzy’s other recipes. I’m wondering if using my thicker cut of halibut at 400° might work? Any feedback is appreciated.
Glad I read all the other reviews, I pre-cooked my veggies first. The flavors of this dish just did not work for me. It wasn’t bad. It was just ok. Not sure what was missing.
This was so much better than I thought it would be! I’m trying to eat healthier and this recipe was a wonderful choice. Quick and easy and flavorful. I will definitely be making this again!
Awesome! Thanks so much, Melissa!
As other commenters have mentioned, this dish really needs to be re-evaluated. There’s definitely potential, but as written I would not recommend making this dish. It’s hard to avoid this turning into soup. The lemon is also extremely overbearing.
Good idea, but this recipe needs to be revised to include some pre-roasting of the vegetables. A max of 15 minutes at 350 did not do it for zucchini and onion. Also, the type of baking pan needs to be specified. The recipe contains too much liquid for a rimmed cookie sheet and parchment, which is what I did. If everything is almost braising in the liquid, it needs to be a large rimmed casserole dish.
Thank you for your feedback, Crystal!
loved this recipe. I only changed soaking the fish in milk for 20 minutes. Cant wait to explore this recipe. I am not sure I want to, less is more. Sliced onion and zuk’s with a mandalin. Keep sharing you are awesome!
Should have read comments first. Not something I would make again. Veggies undercooked and too much lemon.
So easy! And just can make for one person just by halving most of the ingredients. I have tried with green beans, mushrooms and just before baking the parmesan cheese, I layer fresh spinach leaves under the cheese. Simple and healthy dish! (I bake for one in a glass dish in my toaster oven.)
Thanks for the great review, Susan!
I should have read the comments first. Not a keeper in our home, sorry.
First of all, I read the recipe and not the comments before I prepped it. After it was in the oven, I read the comments and I had concerns the veggies would be undercooked. But knowing the cook time was pretty short for veggies, I sliced everything really thin. One other change was I reduced the lemon juice and added a bit of zest from one lemon. PLUS I substituted the seasoning for the Magic seafood seasoning. And oh my, oh my!!!! This is now one of my favorite recipes!!!!
So glad to hear that, Jana! Thank you!
We’ve made this recipe twice in the past two weeks it was so good! We added extra veggies and cooked it at 400 degrees because the fish fillets were thicker than flounder. Easy and absolutely delicious – this recipe is a keeper!
Internet recipes oof! Such a waste of ingrediants. I read all the reviews, cooked the veggies up front after letting the squash drain first and I ended up with a casserole dish full of water, unpleasant fish and a smell/taste that was gross. Threw the entire thing away. Save your ingrediants..this one is not good.