Are you looking for a quick dinner idea? Try this easy pesto flounder recipe with homemade pistachio pesto! The flaky, tender fillets bake in a spiced butter mixture, and the vibrant pesto adds fresh-tasting flavor. Plus, it’s ready in 30 minutes!
Ingredients You’ll Need
- Pistachio Pesto: Finish the baked flounder fillets with homemade pesto sauce. It is easy to make with toasted pistachios, fresh garlic cloves, grated parmesan, fresh basil leaves, lemon juice, lemon zest, and extra virgin olive oil. Use store-bought pesto if you don’t want to make the sauce from scratch.
- Flounder: Fresh flounder is ideal, but frozen fillets work just as well. Thaw the fillets in the refrigerator overnight and pat them dry before using them in this recipe. I often buy frozen flounder from Costco when it goes on sale.
- Spices: Lightly season the fish with dried parsley, kosher salt, black pepper, and red pepper flakes.
Additions and Substitutions
- Experiment with pesto flavors. Swap pistachio pesto for traditional basil pesto, walnut pesto, sun-dried tomato pesto, arugula pesto, or a nut-free version like AIP pesto.
- Spice things up. Consider using skhug or shatta sauce to top the fish for a spicier version instead of pesto.
How to Make Pesto Flounder
The full recipe with measurements is in the recipe card below.
Step 1: Toast the pistachios in a skillet over low heat for 3-5 minutes.
Step 2: Transfer them to a food processor with garlic, parmesan, salt, red pepper flakes, and lemon juice. Process until crumbly. Add the parmesan cheese and basil and process to. Then, stir in the olive oil.
Step 3: Preheat the oven to 325°F (162°C). Then, combine melted butter, kosher salt, black pepper, dried parsley, and red pepper flakes in a small bowl.
Step 4: Arrange the flounder into the baking dish and brush them with the spiced butter mixture.
Step 5: Bake for 10-20 minutes until the flounder reaches 145°F (63°C).
Tip: You may need to increase or decrease the cooking time based on the thickness of the fillets.
Step 6: Remove the pan from the oven and let the fish rest for 5 minutes before topping them with the reserved pistachio pesto.
Expert Tips
- How long do you bake the flounder? Flounder is a delicate fish, so for thin fillets (like the ones pictured), check for doneness around the 10-minute mark. Thicker fillets may need 20-25 minutes to bake.
- How do you know when flounder is done? Pesto flounder will be white and flaky when it’s ready, but use a food thermometer to check the internal temperature of the fish; the safe cooking temperature for flounder is 145°F (62°C).
If you enjoy the pesto flounder, try more seafood recipes!
Serving Suggestions
Serve pesto flounder with sides that highlight its fresh flavors, such as rice pilaf, pesto ricotta salad, air fryer zucchini and squash, risotto allo zafferano, or creamy mashed cauliflower. If you prefer a lighter pairing, serve the fish with peppery arugula and spinach salad or vinegar coleslaw.
What to do with the Leftovers
- Refrigerate: Store the leftover pesto flounder in an airtight container for 1-2 days.
- Reheat: Warm the leftovers in the oven or cook them in the microwave in 30-second increments.
- Repurpose: Add leftover fish to white rice or cauliflower rice to make a protein bowl. Or you can fill a warm corn tortilla with the flounder and top it with purple cabbage coleslaw and chipotle lime sauce for a quick fish taco.
Frequently Asked Questions
What does flounder taste like?
Flounder has a delicate, mild flavor that’s slightly sweet.
More Quick Dinner Ideas:
Pesto Flounder
- Small Bowl
- ½ cup unsalted shelled pistachios, toasted
- 2 garlic cloves, minced
- ¼ cup grated parmesan
- ½ teaspoon kosher salt
- ¼ teaspoon red pepper flakes
- lemon juice, ½ lemon, plus ½ teaspoon of lemon zest
- 3 cups fresh basil leaves, loosely packed
- ½ cup extra-virgin olive oil
- 4 flounder fillets
- 2 tablespoons butter
- ½ teaspoon kosher salt
- ½ teaspoon black pepper, coarse ground
- ¼ teaspoon dried parsley
- ¼ teaspoon red pepper flakes
- ⅓ cup pistachio pesto
- Toast the pistachios in a skillet over low heat for 3-5 minutes.
- Transfer them to a food processor with garlic, parmesan, salt, red pepper flakes, and lemon juice. Process until crumbly. Add the parmesan cheese and basil and process to. Then, stir in the olive oil.
- Preheat the oven to 325°F (162°C). Then, combine melted butter, salt, black pepper, dried parsley, and red pepper flakes in a small bowl.
- Arrange the flounder into the baking dish and brush them with the spiced butter mixture.
- Bake for 10-20 minutes until the flounder reaches 145°F (63°C).Tip: You may need to increase or decrease the cooking time based on the thickness of the fillets.
- Remove the pan from the oven and let the fish rest for 5 minutes before topping them with the reserved pistachio pesto.
- How long do you bake the flounder? Flounder is a delicate fish, so for thin fillets (like the ones pictured), check for doneness around the 10-minute mark. Thicker fillets may need 20-25 minutes to bake.
- How do you know when flounder is done? Pesto flounder will be white and flaky when it’s ready, but use a food thermometer to check the internal temperature of the fish; the safe cooking temperature for flounder is 145°F (62°C).
- The nutritional information shown is an estimate provided by an online nutrition calculator. It should not be considered a substitute for professional advice.
Ali
Friday 26th of May 2023
Great recipe!
Tressa Jamil
Monday 2nd of October 2023
I am thrilled you enjoyed it. Thank you for taking the time to rate the recipe and leave a comment.
Emily Reynolds
Friday 26th of May 2023
This baked flounder recipe is a weeknight dinner winner!The fillets melt in your mouth, and the homemade pesto adds so much flavor. My family loved it!
Tressa Jamil
Monday 2nd of October 2023
You are so right about the fillets melting in your mouth. I may need to add that to the post. I am so happy this is a meal your whole family enjoyed.